superheater test sections: Topics by WorldWideScience.org

Sample records for superheater test sections

The CP 1 type separators-superheaters

International Nuclear Information System (INIS)

Palacio, G.

1984-01-01

Analysis of the functionnement of the separators superheaters in the first French 900 MW PWR units (Fessenhein 1-2 and Bugey 2-3-4-5) and in the program CP 1 units: localization of the separators superheaters, design, tests and choice of the materials, description of the separators superheaters (shells, separators, superheater bundles, internal lagging, purging tank and condensate stank, steam line equipments); study of the various operation modes (nominals, transients, malfunctions, conservation during shutdowns) and the in service behaviour of the components; study of the modifications on the CP 1 equipments and their behaviour; description of the measures, tests and on site controls (controls during planned shutdowns and controls during service) [fr
Irradiation of Superheater Test Fuel Elements in the Steam Loop of the R2 Reactor

Energy Technology Data Exchange (ETDEWEB)

Ravndal, F

1967-12-15

The design, fabrication, irradiation results, and post-irradiation examination for three superheater test fuel elements are described. During the spring of 1966 these clusters, each consisting of six fuel rods, were successfully exposed in the superheater loop No. 5 in the R2 reactor for a maximum of 24 days at a maximum outer cladding surface temperature of {approx} 650 deg C. During irradiation the linear heat rating of the rods was in the range 400-535 W/cm. The diameter of the UO{sub 2} pellets was 11.5 and 13.0 mm; the wall thickness of the 20/25 Nb and 20/35 cladding was in every case 0.4 mm. The diametrical gap between fuel and cladding was one of the main parameters and was chosen to be 0.05, 0.07 and 0.10 mm. These experiments, to be followed by one high cladding temperature irradiation ({approx} 750 deg C) and one long time irradiation ({approx} 6000 MWd/tU), were carried out to demonstrate the operational capability of short superheater test fuel rods at steady and transient operational environments for the Marviken superheater fuel elements and also to provide confirmation of design criteria for the same fuel elements.
Superheater corrosion in biomass-fired power plants: Investigation of Welds

DEFF Research Database (Denmark)

Montgomery, Melanie; Carlsen, B; Biede, O

2002-01-01

-fired Masnedø combined heat and power (CHP) plant to investigate corrosion at temperatures higher than that of the actual plant. The highest steam temperature investigated was 570°C. Various alloys of 12-22% chromium content were welded into this test loop. Their corrosion rates were similar and increased...... condense on superheater components. This gives rise to specific corrosion problems not previously encountered in coal-fired power plants. The type of corrosion attack can be directly ascribed to the composition of the deposit and the metal surface temperature. A test superheater was built into the straw...... with temperature. The mechanism of attack was grain boundary attack as a precursor to selective chromium depletion of the alloy. In addition welds coupling various tubes sections were also investigated. It was seen that there was preferential attack around those welds that had a high nickel content. The welds...
Thermomechanical CSM analysis of a superheater tube in transient state

Science.gov (United States)

Taler, Dawid; Madejski, Paweł

2011-12-01

The paper presents a thermomechanical computational solid mechanics analysis (CSM) of a pipe "double omega", used in the steam superheaters in circulating fluidized bed (CFB) boilers. The complex cross-section shape of the "double omega" tubes requires more precise analysis in order to prevent from failure as a result of the excessive temperature and thermal stresses. The results have been obtained using the finite volume method for transient state of superheater. The calculation was carried out for the section of pipe made of low-alloy steel.
Steam separator-superheater with drawing of a fraction of the dried steam

International Nuclear Information System (INIS)

Bessouat, Roger; Marjollet, Jacques.

1976-01-01

This invention concerns a vertical separator-superheater of the steam from a high pressure expansion turbine before it is admitted to an expansion turbine at a lower pressure, by heat exchange with steam under a greater pressure, and drawing of a fraction of the dried steam before it is superheated. Such drawing off is necessary in the heat exchange systems of light water nuclear reactors. Its purpose is to provide a separator-superheater that provides an even flow of non superheated steam and a regular distribution of the steam to be superheated to the various superheating bundles, with a significantly uniform temperature of the casing, thereby preventing thermal stresses and ensuring a minimal pressure drop. The vertical separator-superheater of the invention is divided into several vertical sections comprising as from the central area, a separation area of the steam entrained water and a superheater area and at least one other vertical section with only a separation area of the steam entrained water [fr
Non-contact Measurement of Remaining Thickness of Corroding Superheater Tubes. Phase 2

Energy Technology Data Exchange (ETDEWEB)

Borggreen, Kjeld; Storesund, Jan

2007-12-15

The Electro Magnetic Acoustic Transducer (EMAT) is a contactless thickness gauge for detection of corrosion on superheater tubes; it candidates as substitute for conventional manually operated contact UT transducers. It is the aim of the project to demonstrate the usefulness of two simple EMAT systems, Panametrics and Sonatest, for fast and reliable tube thickness inspections in difficult-to-access superheater sections. The present Phase 2 of the project involves testing of the systems on real compact superheaters in remote operation with the help of a mechanical manipulator designed and built for the purpose. The results are the following: - Both EMAT systems work well when tested in the field during handheld operation on tubes with a moderate thick layer of corrosion products and ash. The practical obtainable speed of cross-panel inspection of easily accessible panels is approximately 6 tubes per minute (6 thickness readings per minute). - The Sonatest system works well when tested in the field during remote operation on heavily corroded superheater tubes with thick ash layer. The Panametrics system was not found suitable for this type of field work. - The mechanical manipulator works well for cross-panel inspection of difficult-to-access superheater sections independent of the tube dimensions and the free space between the panels. In its present design it needs few improvements. - The practical obtainable speed of cross-panel inspection is 3 tubes per minute (3 thickness readings per minute). This speed is limited by the detection rate of the EMAT system and not by the travelling speed of the probe. - Scanning of tubes along their axis was never attempted, because the EMAT instruments were not capable of collecting data coming as a continuous stream. - It cannot be judged from visual alone and hardly from the service data, if a tube or a panel can be inspected by the magnetostrictive EMAT method or not. - The main contribution to failure of the EMAT inspection
Superheater Corrosion In Biomass Boilers: Today's Science and Technology

Energy Technology Data Exchange (ETDEWEB)

Sharp, William (Sandy) [SharpConsultant

2011-12-01

the measured first melting point of fly ash deposits does not necessarily produce a step increase in corrosion rate. Corrosion rate typically accelerates at temperatures below the first melting temperature and mixed deposits may have a broad melting temperature range. Although the environment at a superheater tube surface is initially that of the ash deposits, this chemistry typically changes as the deposits mature. The corrosion rate is controlled by the environment and temperature at the tube surface, which can only be measured indirectly. Some results are counter-intuitive. Two boiler manufacturers and a consortium have developed models to predict fouling and corrosion in biomass boilers in order to specify tube materials for particular operating conditions. It would be very useful to compare the predictions of these models regarding corrosion rates and recommended alloys in the boiler environments where field tests will be performed in the current program. Manufacturers of biomass boilers have concluded that it is more cost-effective to restrict steam temperatures, to co-fire biofuels with high sulfur fuels and/or to use fuel additives rather than try to increase fuel efficiency by operating with superheater tube temperatures above melting temperature of fly ash deposits. Similar strategies have been developed for coal fired and waste-fired boilers. Additives are primarily used to replace alkali metal chloride deposits with higher melting temperature and less corrosive alkali metal sulfate or alkali aluminum silicate deposits. Design modifications that have been shown to control superheater corrosion include adding a radiant pass (empty chamber) between the furnace and the superheater, installing cool tubes immediately upstream of the superheater to trap high chloride deposits, designing superheater banks for quick replacement, using an external superheater that burns a less corrosive biomass fuel, moving circulating fluidized bed (CFB) superheaters from the
Microwave superheaters for fusion

International Nuclear Information System (INIS)

Campbell, R.B.; Hoffman, M.A.; Logan, B.G.

1987-01-01

The microwave superheater uses the synchrotron radiation from a thermonuclear plasma to heat gas seeded with an alkali metal to temperatures far above the temperature of material walls. It can improve the efficiency of the Compact Fusion Advanced Rankine (CFAR) cycle described elsewhere in these proceedings. For a proof-of-principle experiment using helium, calculations show that a gas superheat ΔT of 2000 0 K is possible when the wall temperature is maintained at 1000 0 K. The concept can be scaled to reactor grade systems. Because of the need for synchrotron radiation, the microwave superheater is best suited for use with plasmas burning an advanced fuel such as D- 3 He. 5 refs
Analysis of temperature and stress distribution of superheater tubes after attemperation or sootblower activation

International Nuclear Information System (INIS)

Madejski, Paweł; Taler, Dawid

2013-01-01

Highlights: • The CFD simulation was used to calculate 3D steam and tube wall temperature distributions in the platen superheater. • The CFD results can be used in design of superheaters made of tubes with complex cross-section. • The CFD analysis enables the proper selection of the steel grade. • The transient temperature and stress distributions were calculated using Finite Volume Method. • The detailed analysis prevents superheater tubes from excessive stresses during sootblower or attemperator activation. - Abstract: Superheaters are characterized by high metal temperatures due to higher steam temperature and low heat transfer coefficients on the tube inner surfaces. Superheaters have especially difficult operating conditions, particularly during attemperator and sootblower activations, when temperature and steam flow rate as well as tube wall temperature change with time. A detailed thermo-mechanical analysis of the superheater tubes makes it possible to identify the cause of premature high-temperature failures and aids greatly in the changes in tubing arrangement and improving start-up technology. This paper presents a thermal and strength analysis of a tube “double omega”, used in the steam superheaters in CFB boilers
Overheating failure of superheater suspension tubes of a captive thermal power plant boiler

International Nuclear Information System (INIS)

Bhattacharya, Sova; Amir, Q.M.; Kannan, C.; Mahapatra, S.B.

2000-01-01

Failure of boiler tubes is the foremost cause of forced boiler outages. One of the predominant failure mechanism of boiler tubes is the stress rupture failure in the form of either short term overheating or long term overheating which are normally encountered in superheater and reheater sections working in the creep range. The strength of the boiler tube depends on the stress level as well on the temperature of exposure in the creep range. An increase in either can reduce the time to rupture. Time at the exposure temperature is an important factor based on which the failures are categorised as either short term or long term. Though there is no established time duration criteria demarcating the short or long term stress rupture failures, depending on the various manifestations on the failed samples, one can categorise the failure. This paper addresses one such stress rupture failure in the superheater section of a captive thermal power plant of a refinery. Multiple failures on the suspension coil of a superheater section was investigated for the cause of failure. Laboratory investigation of the failed sample involved visual inspection, dimensional measurements, chemical analysis of internal deposits and microstructural study. On the basis of these, the failure was attributed to deposition of trisodium phosphate carried over by the feed water into the superheater section resulting in chokage and increase in local operating hoop stresses of the tube. The ultimate failure was thus categorised as long term overheating failure. (author)
High-Temperature Graphitization Failure of Primary Superheater Tube

Science.gov (United States)

Ghosh, D.; Ray, S.; Roy, H.; Mandal, N.; Shukla, A. K.

2015-12-01

Failure of boiler tubes is the main cause of unit outages of the plant, which further affects the reliability, availability and safety of the unit. So failure analysis of boiler tubes is absolutely essential to predict the root cause of the failure and the steps are taken for future remedial action to prevent the failure in near future. This paper investigates the probable cause/causes of failure of the primary superheater tube in a thermal power plant boiler. Visual inspection, dimensional measurement, chemical analysis, metallographic examination and hardness measurement are conducted as the part of the investigative studies. Apart from these tests, mechanical testing and fractographic analysis are also conducted as supplements. Finally, it is concluded that the superheater tube is failed due to graphitization for prolonged exposure of the tube at higher temperature.
Critical superheats upon boiling of dissociating liquids

International Nuclear Information System (INIS)

Kolykhan, L.I.; Solov'ev, V.N.

1985-01-01

The experimental data on critical superheats of dissociating liquids, i.e. nitrogen tetroxide and nitrine are presented (nitrine is the solution of nitrogen oxide in nitrogen tetroxide). The experiments with boiling N 2 O 4 have been carried out in the pressure range 0.1-3.0 MPa and with boiling nitrine within the pressure range 0.2-9.0 MPa. The experiments have revealed an anomalous dependence of critical superheats on pressure P, thus at P>=2.5 MPa the critical superheat values exceed the limiting ones, and at P=4.5 MPa this excess amounts to more than 16 K, essentially exceeding the errors of the experiments. The results for N 2 O 4 critical superheats agree with experimental data of other authors. Complex phenomena observed upon boiling of dissociating liquids require further theoretical and experimental studies
High-Speed Imaging of Explosive Droplet Boiling at the Superheat Limit

Science.gov (United States)

Ferris, F. Robert; Hermanson, Jim; Asadollahi, Arash; Esmaeeli, Asghar

2017-11-01

The explosive boiling processes of droplets of diethyl ether (1-2 mm in diameter) at the superheat limit were examined both experimentally and computationally. Experimentally, droplet explosion was studied using a heated bubble column to bring the test droplet to the superheat limit. The droplet fluid was diethyl ether (superheat limit 147 C at 1 bar) with immiscible glycerol employed as the heated host fluid. Tests were carried out at pressures between 0.5 and 4 bar absolute. The pressure rise associated with the explosive boiling event was captured using a piezoelectric quartz pressure transducer with a 1 MHz DAQ system. High-speed imaging of the interfacial behavior during explosive boiling was performed using a Phantom v12.1 camera at a frame rate of up to one million frames per second with the droplets illuminated by diffuse back-lighting. The imaging reveals features of the Rayleigh-Taylor instability at the vapor-liquid interface resulting from the unstable boiling process. Computationally, Direct Numerical Simulations are performed at Southern Illinois University Carbondale to compliment the experimental tests. NSF Award Number 1511152.
Non-contact Measurement of Remaining Thickness of Corroding Superheater Tubes. Phase 1

Energy Technology Data Exchange (ETDEWEB)

Borggreen, Kjeld; Storesund, Jan

2006-10-15

Corrosion of superheaters has become a severe problem in many biomass boilers and incineration plants. This new situation calls for frequent tube wall thickness testing of the superheaters during very short shut-downs. To meet this demand Electro Magnetic Acoustic Transducer (EMAT) candidates as substitute for conventional manually operated contact UT-transducers. The EMAT can contactlessly generate an ultrasonic wave in the interphase between the external oxide and the metal. This means that measurements can be undertaken much quicker and with a much higher coverage simultaneously, without preceding blast operations. It is the aim of the project to demonstrate the usefulness of two simple EMAT systems, Panametrics and Sonatest, for fast and reliable tube thickness inspections in difficult-to-access superheater sections. The present Phase 1 of the project involves testing of the performance of the two systems in laboratory with the following results: 1. Both instruments work well on plate, tube, and pipe samples assuming the presence of an external oxide layer formed at a temperature above approximately 400 deg C. 2. Both instruments work well on all types of ferritic and martensitic steels but not on austenitic steels. 3. Both instruments work well independent of the thickness of the active oxide layer. 4. Both instruments work well independent of tube diameter, wall thickness, and sample width. 5. Both instruments work well over a very large range of wall thicknesses. Minimum tube wall thickness is less than 1.8 mm. 6. The tolerable lift-off (free distance between transducer and tube surface) is 2.4 - 3.0 mm for Panametrics system and 3.6 - 4.8 mm for Sonatest's system. The tolerable lift-off is a measure of the thickness of ash deposits, which can be tolerated on the tube surface as well as the misplacement, which can be tolerated in case of remote tube testing. 7. The tolerable off-set between tube axis and probe axis is very large for both instruments (10
Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings -- Phase 2 field testing

Energy Technology Data Exchange (ETDEWEB)

Blough, J.L. [Foster Wheeler Development Corp., Livingston, NJ (United States)

1996-08-01

In Phase 1 of this project, a variety of developmental and commercial tubing alloys and claddings was exposed to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. Phase 2 (in situ testing) has exposed samples of 347, RA85H, HR3C, 253MA, Fe{sub 3}Al + 5Cr, 310 modified, NF 709, 690 clad, and 671 clad for over 10,000 hours to the actual operating conditions of a 250-MW coal-fired boiler. The samples were installed on air-cooled, retractable corrosion probes, installed in the reheater cavity, controlled to the operating metal temperatures of an existing and advanced-cycle, coal-fired boiler. Samples of each alloy are being exposed for 4,000, 12,000, and 16,000 hours of operation. The present results are for the metallurgical examination of the corrosion probe samples after approximately 4,400 hours of exposure.
Neural network for prediction of superheater fireside corrosion

Energy Technology Data Exchange (ETDEWEB)

Makkonen, P [Foster Wheeler Energia Oy, Karhula R and D Center, Karhula (Finland)

1999-12-31

Superheater corrosion causes vast annual losses to the power companies. If the corrosion could be reliably predicted, new power plants could be designed accordingly, and knowledge of fuel selection and determination of process conditions could be utilized to minimize superheater corrosion. If relations between inputs and the output are poorly known, conventional models depending on corrosion theories will fail. A prediction model based on a neural network is capable of learning from errors and improving its performance as the amount of data increases. The neural network developed during this study predicts superheater corrosion with 80 % accuracy at early stage of the project. (orig.) 10 refs.
Neural network for prediction of superheater fireside corrosion

Energy Technology Data Exchange (ETDEWEB)

Makkonen, P. [Foster Wheeler Energia Oy, Karhula R and D Center, Karhula (Finland)

1998-12-31

Superheater corrosion causes vast annual losses to the power companies. If the corrosion could be reliably predicted, new power plants could be designed accordingly, and knowledge of fuel selection and determination of process conditions could be utilized to minimize superheater corrosion. If relations between inputs and the output are poorly known, conventional models depending on corrosion theories will fail. A prediction model based on a neural network is capable of learning from errors and improving its performance as the amount of data increases. The neural network developed during this study predicts superheater corrosion with 80 % accuracy at early stage of the project. (orig.) 10 refs.
Adaptive Superheat Control of a Refrigeration Plant using Backstepping

DEFF Research Database (Denmark)

Rasmussen, Henrik

2008-01-01

This paper proposes a novel method for superheat and capacity control of refrigeration systems. The new idea is to control the superheat by the compressor speed and capacity by the refrigerant flow. This gives a highly nonlinear transfer operator from compressor speed input to the superheat output....... A new low order nonlinear model of the evaporator is developed and used in a backstepping design of an adaptive nonlinear controller. The stability of the proposed method is validated theoretically by Lyapunov analysis and experimental results shows the performance of the system for a wide range...
Current Status of Superheat Spray Modeling With NCC

Science.gov (United States)

Raju, M. S.; Bulzan, Dan L.

2012-01-01

An understanding of liquid fuel behavior at superheat conditions is identified to be a topic of importance in the design of modern supersonic engines. As a part of the NASA's supersonics project office initiative on high altitude emissions, we have undertaken an effort to assess the accuracy of various existing CFD models used in the modeling of superheated sprays. As a part of this investigation, we have completed the implementation of a modeling approach into the national combustion code (NCC), and then applied it to investigate the following three cases: (1) the validation of a flashing jet generated by the sudden release of pressurized R134A from a cylindrical nozzle, (2) the differences between two superheat vaporization models were studied based on both hot and cold flow calculations of a Parker-Hannifin pressure swirl atomizer, (3) the spray characteristics generated by a single-element LDI (Lean Direct Injector) experiment were studied to investigate the differences between superheat and non-superheat conditions. Further details can be found in the paper.
Superheat in magma oceans

Science.gov (United States)

Jakes, Petr

1992-01-01

The existence of 'totally molten' planets implies the existence of a superheat (excess of heat) in the magma reservoirs since the heat buffer (i.e., presence of crystals having high latent heat of fusion) does not exist in a large, completely molten reservoir. Any addition of impacting material results in increase of the temperature of the melt and under favorable circumstances heat is stored. The behavior of superheat melts is little understood; therefore, we experimentally examined properties and behavior of excess heat melts at atmospheric pressures and inert gas atmosphere. Highly siliceous melts (70 percent SiO2) were chosen for the experiments because of the possibility of quenching such melts into glasses, the slow rate of reaction in highly siliceous composition, and the fact that such melts are present in terrestrial impact craters and impact-generated glasses. Results from the investigation are presented.

Superheater fouling in a BFB boiler firing wood-based fuel blends

NARCIS (Netherlands)

Stam, A.F.; Haasnoot, K.; Brem, Gerrit

2014-01-01

Four different fuel blends have been fired in a 28 MWel BFB. Wood pellets (test 0) were not problematic for about ten years, contrary to a mixture of demolition wood, wood cuttings, compost overflow, paper sludge and roadside grass (test 1) which caused excessive fouling at a superheater bundle
Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings -- Phase 2 field testing

Energy Technology Data Exchange (ETDEWEB)

Blough, J.L.; Seitz, W.W.; Girshik, A. [Foster Wheeler Development Corp., Livingston, NJ (United States)

1998-06-01

In Phase 1 of this project, laboratory experiments were performed on a variety of developmental and commercial tubing alloys and claddings by exposing them to fireside corrosion tests which simulated a superheater or reheater in a coal-fired boiler. Phase 2 (in situ testing) has exposed samples of 347, RA85H, HR3C, RA253MA, Fe{sub 3}Al + 5Cr, Ta-modified 310, NF 709, 690 clad, 671 clad, and 800HT for up to approximately 16,000 hours to the actual operating conditions of a 250-MW, coal-fired boiler. The samples were installed on air-cooled, retractable corrosion probes, installed in the reheater cavity, and controlled to the operating metal temperatures of an existing and advanced-cycle, coal-fired boiler. Samples of each alloy were exposed for 4,483, 11,348, and 15,883 hours of operation. The present results are for the metallurgical examination of the corrosion probe samples after the full 15,883 hours of exposure. A previous topical report has been issued for the 4,483 hours of exposure.
Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings -- Phase 2

Energy Technology Data Exchange (ETDEWEB)

Blough, J.L.; Seitz, W.W. [Foster Wheeler Development Corp., Livingston, NJ (United States)

1997-12-01

In Phase 1 a variety of developmental and commercial tubing alloys and claddings were exposed to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. Phase 2 (in situ testing) has exposed samples of 347 RA-85H, HR3C, 253MA, Fe{sub 3}Al + 5Cr, 310 Ta modified, NF 709, 690 clad, and 671 clad for approximately 4,000, 12,000, and 16,000 hours to the actual operating conditions of a 250-MW coal-fired boiler. The samples were assembled on an air-cooled, retractable corrosion probe, the probe was installed in the reheater activity of the boiler and controlled to the operating metal temperatures of an existing and advanced-cycle coal-fired boiler. The results will be presented for the preliminary metallurgical examination of the corrosion probe samples after 16,000 hours of exposure. Continued metallurgical and interpretive analysis is still on going.
Simulasi Thermal Stress Pada Tube Superheater Package Boiler

OpenAIRE

Hamdani

2013-01-01

This project investigates the thermal stress behavior and the mechanisms of superheater tube failure with experimental method and numerical analysis. First of all the procedures for failure analysis were applied to determine the root cause of them. A visual assessment of boiler critical pressure parts was carried out, and then the failed tube is examined by nondestructive evaluation. For the numerical domain, initially the elastic solution for a superheater tube subjected to an internal press...
A steam separator-superheater apparatus

International Nuclear Information System (INIS)

Androw, Jean; Bessouat, Roger; Peyrelongue, J.-P.

1973-01-01

Description is given of a separator-superheater apparatus comprising an outer enclosure containing a separating-unit and a steam superheating unit according to the main patent. The present addition relates to an improvement in that apparatus, characterized in that the separating unit and the superheating unit, mounted in two distinct portions of the outer enclosure, are divided into the same number of sub-units of each unit being identical and operating in parallel, and in that to each separator sub-unit is associated a superheater sub-unit, said sub-units being mounted in series and located in one in the other of the enclosure two portions, respectively. This can be applied to the treatment of the exhaust steam of a turbine high pressure body, prior to re-injecting said steam into the low pressure body [fr
Nonlinear Superheat Control of a Refrigeration Plant using Backstepping

DEFF Research Database (Denmark)

Rasmussen, Henrik

2008-01-01

This paper proposes a novel method for superheat and capacity control of refrigeration systems. The main idea is to control the superheat by the compressor speed and capacity by the refrigerant flow. A new low order nonlinear model of the evaporator is developed and used in a backstepping design...... of a nonlinear controller. The proposed method is validated by experimental results....
Automatic Tuning of the Superheat Controller in a Refrigeration Plant

DEFF Research Database (Denmark)

Rasmussen, Henrik; Thybo, Claus; Larsen, Lars F. S.

2006-01-01

This paper proposes an automatic tuning of the superheat control in a refrigeration system using a relay method. By means of a simple evaporator model that captures the important dynamics and non-linearities of the superheat a gain-scheduling that compensates for the variation of the process gain...
Prevention of superheater corrosion caused by chlorine; Tulistimien kloorikorroosion estaeminen

Energy Technology Data Exchange (ETDEWEB)

Roppo, J. [Kvaerner Power Oy, Tampere (Finland)

2006-12-19

Combustion of CO{sub 2}-neutral fuels is becoming more attractive and common method to decrease CO2 emissions of energy production. Also well managed and controlled combustion of waste fractions compared to their landfilling produces much less greenhouse gas emissions. In combustion of these fuels in high efficiency power plants notably increased superheater corrosion risk is prevailing, mainly caused by chlorine. Typical such fuels are forest, agricultural and household residues, biological sludge's of pulp and paper industry and RDF made from separated municipal and industrial solid waste. The goal of the project is to develop clearly cheaper and more effective method to protect superheaters, which enables combustion of biomass and waste fuels with higher energy shares. Tests in pilot and full scale power plants will reveal the potential and applicability of the developed method for commercial use. (orig.)
Fireside corrosion of superheaters/reheaters in advanced power plants

Energy Technology Data Exchange (ETDEWEB)

Syed, A.U.; Simms, N.J.; Oakey, J.E. [Cranfield Univ. (United Kingdom). Energy Technology Centre

2010-07-01

The generation of increasing amounts of electricity while simultaneously reducing environmental emissions (CO{sub 2}, SO{sub 2}, NO{sub x} particles, etc) has become a goal for the power industry worldwide. Co-firing biomass and coal in new advanced pulverised fuel power plants is one route to address this issue, since biomass is regarded as a CO{sub 2} neutral fuel (i.e. CO{sub 2} uptake during its growth equals the CO{sub 2} emissions produced during its combustion) and such new advanced power plants operate at higher efficiencies than current plants as a result of using steam systems with high temperatures and pressures. However, co-firing has the potential to cause significant operational challenges for such power plants as amongst other issues, it will significantly change the chemistry of the deposits on the heat exchanger surfaces and the surrounding gas compositions. As a result these critical components can experience higher corrosion rates, and so shorter lives, causing increased operational costs, unless the most appropriate materials are selected for their construction. This paper reports the results of a series of 1000 hour laboratory corrosion tests that have been carried out in controlled atmosphere furnaces, to assess the effect of biomass/coal co-firing on the fireside corrosion of superheaters/reheaters. The materials used for the tests were one ferritic alloy (T92), two austenitic alloys (347HFG and HR3C) and one nickel based alloy (alloy 625). Temperatures of 600 and 650 C were used to represent the metal temperatures in advanced power plants. During these exposures, traditional mass change data were recorded as the samples were recoated with the simulated deposits. After these exposures, cross-sections through samples were prepared using standard metallographic techniques and then analysed using SEM/EDX. Pre-exposure micrometer and post-exposure image analyser measurements were used so that the metal wastage could be calculated. These data are
Single Temperature Sensor Superheat Control Using a Novel Maximum Slope-seeking Method

DEFF Research Database (Denmark)

Vinther, Kasper; Rasmussen, Henrik; Izadi-Zamanabadi, Roozbeh

2013-01-01

Superheating of refrigerant in the evaporator is an important aspect of safe operation of refrigeration systems. The level of superheat is typically controlled by adjusting the flow of refrigerant using an electronic expansion valve, where the superheat is calculated using measurements from...
Nonlinear Superheat and Evaporation Temperature Control of a Refrigeration Plant

DEFF Research Database (Denmark)

Rasmussen, Henrik; Thybo, Claus; Larsen, Lars F. S.

2006-01-01

This paper proposes novel control of the superheat of the evaporator in a refrigeration system. A new model of the evaporator is developed and based on this model the superheat is transferred to a referred variable. It is shown that control of this variable leads to a linear system independent...... of the working point. The model also gives a method for control of the evaporation temperature. The proposed method is validated by experimental results....
Remaining Life Estimation Of Secondary Superheater Outlet On Industrial Electrical Boiler

International Nuclear Information System (INIS)

Soedardjo; Andryansyah; Arhatari, B.D.; Natsir, Muhammad; Triyadi, Ari; Farokhi

2001-01-01

Remaining life estimation of secondary superheater header outlet (SSHO) on industrial electrical boiler has been carried out. Estimation conducted by the observation of microstructure cavitation development based on Neubauer and Wedel theory. The result is available for isolated cavitation development present yet. That Secondary Superheater Outlet component is in good condition after 14 years operated and predicted could be operated for 36 years again
Oxidation rate in ferritic superheater materials

International Nuclear Information System (INIS)

Falk, I.

1992-05-01

On the steam side of superheater tubes, compact oxide layers are formed which have a tendency to crack and flake off (exfoliate). Oxide particles then travel with the steam and can give rise to erosion damage in valves and on turbine blades. In an evaluation of conditions in superheater tubes from Swedish power boilers, it was found that the exfoliation frequency for one material quality (SS 2218) was greater than for other qualities. Against this background, a literature study has been carried out in order to determine which mechanisms govern the build-up of oxide and the exfoliation phenomenon. The study reveals that the oxide morphology is similar on all ferritic steels with Cr contents up to 5%. and that the oxide properties can therefore be expected to be similar. The reason why the exfoliation frequency is greater for tubes of SS 2218 is probably that the tubes have been exposed to higher temperatures. SS 2218 (2.25 Cr) is normally used in a higher temperature range which is accompanied by improved strength data as compared with SS 2216 (1 Cr). The principal cause of the exfoliation is said to be stresses which arise in the oxide during the cooling-down process associated with shutdowns. The stresses give rise to longitudinal cracks in the oxide, and are formed as a result of differences in thermal expansion between the oxide and the tube material. In addition, accounts are presented of oxidation constants and growth velocities, and thickness and running time. These data constitute a valuable basis for practical estimates of the operating temperature in routine checks and investigations into damage in superheater tubes. (au)
Lifetime evaluation of superheater tubes exposed to steam oxidation, high temperature corrosion and creep

Energy Technology Data Exchange (ETDEWEB)

Henriksen, N [Elsamprojekt A/S, Faelleskemikerne, Fredericia (Denmark); Hede Larsen, O; Blum, R [I/S Fynsvaerket, Faelleskemikerne, Odense (Denmark)

1996-12-01

Advanced fossil fired plants operating at high steam temperatures require careful design of the superheaters. The German TRD design code normally used in Denmark is not precise enough for the design of superheaters with long lifetimes. The authors have developed a computer program to be used in the evaluation of superheater tube lifetime based on input related to tube dimensions, material, pressure, steam temperature, mass flux, heat flux and estimated corrosion rates. The program is described in the paper. As far as practically feasible, the model seems to give a true picture of the reality. For superheaters exposed to high heat fluxes or low internal heat transfer coefficients as is the case for superheaters located in fluidized bed environments or radiant environments, the program has been extremely useful for evaluation of surface temperature, oxide formation and lifetime. The total uncertainty of the method is mainly influenced by the uncertainty of the determination of the corrosion rate. More precise models describing the corrosion rate as a function of tube surface temperature, fuel parameters and boiler parameters need to be developed. (au) 21 refs.
DYNAM, Once Through Boiling Flow with Steam Superheat, Laplace Transformation

International Nuclear Information System (INIS)

Schlueter, G.; Efferding, L.E.

1973-01-01

1 - Description of problem or function: DYNAM performs a dynamic analysis of once-through boiling flow oscillations with steam superheat. The model describing the superheat regime (single- phase, variable density fluid) for subcritical pressure operation is also applicable to the study of once-through operation using supercritical pressure water. 2 - Method of solution: Linearized partial differential conservation equations are solved using Laplace transformation of the temporal terms and integration of the spatial variations. DYNAM is written in complex variable notation. 3 - Restrictions on the complexity of the problem - Maxima of: 30 intervals used to describe the power distribution in the non-boiling and boiling regions, 29 boiling nodes, 7 intervals and corresponding friction multipliers read in per case, 14 exit qualities read in per case, 40 superheat nodes, 10 coefficients read in for the phi 2 vs, x-polynomial fit, 48 frequencies at which open-loop frequency response is desired, 48 frequencies at which signal output is desired
FARO tests corium-melt cooling in water pool: Roles of melt superheat and sintering in sediment

Energy Technology Data Exchange (ETDEWEB)

Hwang, Gisuk [Department of Mechanical Engineering, Wichita State University, Wichita, KS 67260 (United States); Kaviany, Massoud [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Division of Advance Nuclear Engineering, POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Moriyama, Kiyofumi [Division of Advance Nuclear Engineering, POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Park, Hyun Sun, E-mail: hejsunny@postech.ac.kr [Division of Advance Nuclear Engineering, POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Hwang, Byoungcheol; Lee, Mooneon; Kim, Eunho; Park, Jin Ho [Division of Advance Nuclear Engineering, POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Nasersharifi, Yahya [Department of Mechanical Engineering, Wichita State University, Wichita, KS 67260 (United States)

2016-08-15

Highlights: • The numerical approach for FARO experimental data is suggested. • The cooling mechanism of ex-vessel corium is suggested. • The predicted minimum pool depth for no cake formation is suggested. - Abstract: The FARO tests have aimed at understanding an important severe accident mitigation action in a light water reactor when the accident progresses from the reactor pressure vessel boundary. These tests have aimed to measure the coolability of a molten core material (corium) gravity dispersed as jet into a water pool, quantifying the loose particle diameter distribution and fraction converted to cake under range of initial melt superheat and pool temperature and depth. Under complete hydrodynamic breakup of corium and consequent sedimentation in the pool, the initially superheated corium can result in debris bed consisting of discrete solid particles (loose debris) and/or a solid cake at the bottom of the pool. The success of the debris bed coolability requires cooling of the cake, and this is controlled by the large internal resistance. We postulate that the corium cake forms when there is a remelting part in the sediment. We show that even though a solid shell forms around the melt particles transiting in the water pool due to film-boiling heat transfer, the superheated melt allows remelting of the large particles in the sediment (depending on the water temperature and the transit time) using the COOLAP (Coolability Analysis with Parametric fuel-cooant interaction models) code. With this remelting and its liquid-phase sintering of the non-remelted particles, we predict the fraction of the melt particles converting to a cake through liquid sintering. Our predictions are in good agreement with the existing results of the FARO experiments. We address only those experiments with pool depths sufficient/exceeding the length required for complete breakup of the molten jet. Our analysis of the fate of molten corium aimed at devising the effective
Influence of Superheated Steam Temperature Regulation Quality on Service Life of Boiler Steam Super-Heater Metal

Directory of Open Access Journals (Sweden)

G. T. Kulakov

2009-01-01

Full Text Available The paper investigates influence of change in quality of superheated steam temperature regulations on service life of super-heater metal. А dependence between metal service life and dispersion value for different steel grades has been determined in the paper. Numerical values pertaining to increase of super-heater metal service life in case of transferring from manual regulation to standard system of automatic regulation (SAR have been determined and in case of transferring from standard SAR to improved SAR. The analysis of tabular data and plotted dependencies makes it possible to conclude that any change in conditions of convection super-heater metal work due to better quality of the regulation leads to essential increase of time period which is left till the completion of the service life of a super-heater heating surface.
Alkali chloride induced corrosion of superheaters under biomass firing conditions: Improved insights from laboratory scale studies

DEFF Research Database (Denmark)

Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

2015-01-01

One of the major operational challenges experienced by power plants firing biomass is the high corrosion rate of superheaters. This limits the outlet steam temperature of the superheaters and consequently, the efficiency of the power plants. The high corrosion rates have been attributed to the fo......One of the major operational challenges experienced by power plants firing biomass is the high corrosion rate of superheaters. This limits the outlet steam temperature of the superheaters and consequently, the efficiency of the power plants. The high corrosion rates have been attributed......, [1–3]). However, complete understanding of the corrosion mechanism under biomass-firing conditions has not yet been achieved. This is attributed partly to the complex nature of the corrosion process since there are many species produced from fuel combustion which can interact with one another...... and the steel surface. Many studies have focused on specific parameters such as, deposit composition (KCl, K2SO4, K2CO3, etc.) or gas species such as HCl, SO2, H2O [4–6], however, more research is necessary to understand the interaction of deposits and gas mixtures with each other and metallic superheater...
Contamination prevention of superheaters and reheaters during initial startup and operation

International Nuclear Information System (INIS)

Gabrielli, F.; Sylvester, W.R.; Thimot, G.W.

1976-01-01

The general precautions that should be taken to minimize the potential for harmful contamination or oxygen corrosion of power plant superheaters and reheaters during the period from field storage through operation are discussed and summarized. Present boiler industry start-up and operating practices intended to minimize the introduction of solids to the superheater are, as proven by experience, adequate to avoid contamination-related problems. No basic changes to general industry practice are necessary. What is needed, however, is a continuing awareness of the potential for contamination-related problems so that in the specific application of these practices all likely sources of contamination will be considered
Phase Identification and Internal Stress Analysis of Steamside Oxides on Plant Exposed Superheater Tubes

DEFF Research Database (Denmark)

Pantleon, Karen; Montgomery, Melanie

2012-01-01

During long-term, high-temperature exposure of superheater tubes in thermal power plants, various oxides are formed on the inner side (steamside) of the tubes, and oxide spallation is a serious problem for the power plant industry. Most often, oxidation in a steam atmosphere is investigated...... in laboratory experiments just mimicking the actual conditions in the power plant for simplified samples. On real plant-exposed superheater tubes, the steamside oxides are solely investigated microscopically. The feasibility of X-ray diffraction for the characterization of steamside oxidation on real plant......-exposed superheater tubes was proven in the current work; the challenges for depth-resolved phase analysis and phase-specific residual stress analysis at the inner side of the tubes with concave surface curvature are discussed. Essential differences between the steamside oxides formed on two different steels...

Survey of the current state of knowledge of incipient boiling superheat in sodium

International Nuclear Information System (INIS)

Greer, B.

1979-01-01

Superheat data obtained by various investigators indicate that many parameters affect this phenomenon. Controlling parameters appear to be inert gas concentration, oxide concentration, system pressure, pressure-temperature history, rate of temperature rise, heat flux, flow rate, operating time on the system, surface conditions, and radiation. Of these, the two believed most influential in controlling incipient boiling superheat are the inert gas concentration and oxide concentration. Experimental results for the heat flux and rate of temperature rise appear to be the most inconsistent
SEM Investigation of Superheater Deposits from Biomass-Fired Boilers

DEFF Research Database (Denmark)

Jensen, Peter Arendt; Frandsen, Flemming; Hansen, Jørn

2004-01-01

, mature superheater deposit samples were extracted from two straw-fired boilers, Masnedø and Ensted, with fuel inputs of 33 MWth and 100 MWth, respectively. SEM (scanning electron microscopy) images and EDX (energy dispersive X-ray) analyses were performed on the deposit samples. Different strategies...
Nonlinear superheat and capacity control of a refrigeration plant

DEFF Research Database (Denmark)

Rasmussen, Henrik; Larsen, Lars F. S.

2009-01-01

This paper proposes a novel method for superheat and capacity control of refrigeration systems. A new low order nonlinear model of the evaporator is developed and used in a backstepping design of a nonlinear controller. The stability of the proposed method is validated theoretically by Lyapunov...
Effective new chemicals to prevent corrosion due to chlorine in power plant superheaters

Energy Technology Data Exchange (ETDEWEB)

Martti Aho; Pasi Vainikka; Raili Taipale; Patrik Yrjas [VTT, Jyvaeskylae (Finland)

2008-05-15

Firing or co-firing of biomass in efficient power plants can lead to high-temperature corrosion of superheaters due to condensation of alkali chlorides into superheater deposits. Corrosion can be prevented if a significant portion of the alkali chlorides present in the flue gases is destroyed before reaching the superheaters. The alkali capturing power of aluminium and ferric sulphates was determined in a pilot-scale fluidised bed (FB) reactor. The reagents were added in solution, through a spraying nozzle, to the upper part of the freeboard. Both reagents, at economical dosages, fast and effectively destroyed the alkali chlorides by producing sufficient SO{sub 3} for the sulphation. Both the mass flow rate and type of sulphate affected the sulphation ability. Thus, the cation, too, plays a role in the reaction. The required chemical dosage is not directly proportional to the S{sub reagent}/Cl{sub 2fuel} ratio because alkali chlorides must compete with calcium and magnesium oxides and probably also with alkali oxides for the available SO{sub 3}. 17 refs., 16 figs., 1 tab.
Research on the Superheater Material Properties for USC Boiler with 700°C Steam Parameter

Science.gov (United States)

Chongbin, Wang; Xueyuan, Xu; Yufeng, Zhu; Yongqiang, Jin; Hui, Tong; Yu, Wang; Xiaoli, Lu

This paper discusses the materials' properties of superheater for 700°C USC boiler, including Sanicro25, HR6W, 617mod and 740H, and analyzes the range of applicable temperature of superheater made of different tubes, such as T91, T92, Super304H, TP310HCbN, Sanicro25, HR6W, 617Mod and 740H. In addition, some suggestions on the material selection have been proposed.
Integrated boiler, superheater, and decomposer for sulfuric acid decomposition

Science.gov (United States)

Moore, Robert [Edgewood, NM; Pickard, Paul S [Albuquerque, NM; Parma, Jr., Edward J.; Vernon, Milton E [Albuquerque, NM; Gelbard, Fred [Albuquerque, NM; Lenard, Roger X [Edgewood, NM

2010-01-12

A method and apparatus, constructed of ceramics and other corrosion resistant materials, for decomposing sulfuric acid into sulfur dioxide, oxygen and water using an integrated boiler, superheater, and decomposer unit comprising a bayonet-type, dual-tube, counter-flow heat exchanger with a catalytic insert and a central baffle to increase recuperation efficiency.
A fault tolerant superheat control strategy for supermarket refrigeration systems

DEFF Research Database (Denmark)

Vinther, Kasper; Izadi-Zamanabadi, Roozbeh; Rasmussen, Henrik

2013-01-01

, based on a maximum slope-seeking control method and only a single temperature sensor, is developed to drive the evaporator outlet temperature to a level that gives a suitable superheat of the refrigerant. The FTC strategy requires no a priori system knowledge or additional hardware and functions...
Tuning and performance evaluation of PID controller for superheater steam temperature control of 200 MW boiler using gain phase assignment algorithm

Science.gov (United States)

Begum, A. Yasmine; Gireesh, N.

2018-04-01

In superheater, steam temperature is controlled in a cascade control loop. The cascade control loop consists of PI and PID controllers. To improve the superheater steam temperature control the controller's gains in a cascade control loop has to be tuned efficiently. The mathematical model of the superheater is derived by sets of nonlinear partial differential equations. The tuning methods taken for study here are designed for delay plus first order transfer function model. Hence from the dynamical model of the superheater, a FOPTD model is derived using frequency response method. Then by using Chien-Hrones-Reswick Tuning Algorithm and Gain-Phase Assignment Algorithm optimum controller gains has been found out based on the least value of integral time weighted absolute error.
The Phenomenon of Superheat of Liquids: In Memory of Vladimir P. Skripov

Science.gov (United States)

Skripov, P. V.; Skripov, A. P.

2010-05-01

This article is devoted to the memory of Vladimir P. Skripov (1927-2006). He has received worldwide recognition for his monograph on metastable liquids published in 1972 (the English edition was published in 1974). We briefly discuss some studies deal with the phenomenon of attainable superheat of liquids and with measurements of thermophysical properties of liquids under conditions of a moderate degree of superheat. Main attention is paid to the studies performed by V.P. Skripov and his research group in the 1960s and 1970s. Experimental methods which provided break-throughs in research on both spontaneous boiling-up kinetics and substance properties (the specific volume, isobaric heat capacity, ultrasound speed, and viscosity) in super-heated states are presented.
A Stochastic mesoscopic model for predicting the globular grain structure and solute redistribution in cast alloys at low superheat

International Nuclear Information System (INIS)

Nastac, Laurentiu; El Kaddah, Nagy

2012-01-01

It is well known that casting at low superheat has a strong influence on the solidification morphology and macro- and microstructures of the cast alloy. This paper describes a stochastic mesoscopic solidification model for predicting the grain structure and segregation in cast alloy at low superheat. This model was applied to predict the globular solidification morphology and size as well as solute redistribution of Al in cast Mg AZ31B alloy at superheat of 5°C produced by the Magnetic Suspension Melting (MSM) process, which is an integrated containerless induction melting and casting process. The castings produced at this low superheat have fine globular grain structure, with an average grain size of 80 μm, which is about 3 times smaller than that obtained by conventional casting techniques. The stochastic model was found to reasonably predict the observed grain structure and Al microsegregation. This makes the model a useful tool for controlling the structure of cast magnesium alloys.
Review about corrosion of superheaters tubes in biomass plants

International Nuclear Information System (INIS)

Berlanga-Labari, C.; Fernandez-Carrasquilla, J.

2006-01-01

The design of new biomass-fired power plants with increased steam temperature raises concerns of high-temperature corrosion. The high potassium and chlorine contents in many biomass, specially in wheat straw, are potentially harmful elements with regard to corrosion. Chlorine may cause accelerated corrosion resulting in increased oxidation, metal wastage, internal attack, void formations and loose non-adherent scales. The most severe corrosion problems in biomass-fired systems are expected to occur due to Cl-rich deposits formed on superheater tubes. In the first part of this revision the corrosion mechanism proposed are described in function of the conditions and compounds involved. The second part is focused on the behaviour of the materials tested so far in the boiler and in the laboratory. First the traditional commercial alloys are studied and secondly the new alloys and the coasting. (Author). 102 refs
Preventing superheater corrosion by additives; Tulistimien kloorikorroosion estaeminen lisaeainein

Energy Technology Data Exchange (ETDEWEB)

Aho, M.; Vainikka, P. [VTT, Espoo (Finland); Skrifvars, B.J.; Yrjas, P. [Aabo Akademi, Process Chemistry, Turku (Finland)

2006-12-19

The new superheater protection methods enable combustion of demanding biomass with higher portions than at present. This benefit reduces CO{sub 2} emissions from energy production and the use of demanding biomass in energy production will extend replacing biowaste landfilling with strong CH{sub 4} formation. The results assist also to meet the goals of the use of logging residues in energy production in Finland. (orig.)
CLUMPED LIGHT WATER MODERATED UO$sub 2$ SUPERHEAT CRITICALS. PART II. ANALYSIS

Energy Technology Data Exchange (ETDEWEB)

Petersen, G. T.

1963-11-15

Critical and subcritical reactivity measurements on an EVESR-type core, using EVESR UO/sub 2/ superheat fuel elements, are analyzed in order to obtain a physics design model for use in the EVESR. (T.F.H.)
Superheater fireside corrosion mechanisms in MSWI plants: Lab-scale study and on-site results

Energy Technology Data Exchange (ETDEWEB)

Brossard, J.M.; Chaucherie, X.; Nicol, F. [Veolia Environnement R and D, Zone Portuaire de Limay, 291 Avenue Dreyfous Ducas, Limay 78520 (France); Diop, I. [Veolia Environnement R and D, Zone Portuaire de Limay, 291 Avenue Dreyfous Ducas, Limay 78520 (France); Institut Jean Lamour, departement Chimie et physique des solides et des surfaces, UMR 7198 CNRS - Universite Henri Poincare Nancy 1, Vandoeuvre-Les-Nancy (France); Rapin, C.; Vilasi, M. [Institut Jean Lamour, departement Chimie et physique des solides et des surfaces, UMR 7198 CNRS - Universite Henri Poincare Nancy 1, Vandoeuvre-Les-Nancy (France)

2011-06-15

Combustion of municipal waste generates highly corrosive gases (HCl, SO{sub 2}, NaCl, KCl, and heavy metals chlorides) and ashes containing alkaline chlorides and sulfates. Currently, corrosion phenomena are particularly observed on superheater's tubes. Corrosion rates depend mainly on installation design, operating conditions i.e., gas and steam temperature and velocity of the flue gas containing ashes. This paper presents the results obtained using an innovative laboratory-scale corrosion unit, which simulates MSWI (Municipal Solid Waste Incineration) boilers conditions characterized by a temperature gradient at the metal tube in the presence of corrosive gases and ashes. The presented corrosion tests were realized on carbon steel at fixed metal temperature (400 C). The influence of the flue gas temperature, synthetic ashes composition, and flue gas flow pattern were investigated. After corrosion test, cross sections of tube samples were characterized to evaluate thickness loss and estimate corrosion rate while the elements present in corrosion layers were analyzed. Corrosion tests were carried out twice in order to validate the accuracy and reproducibility of results. First results highlight the key role of molten phase related to the ash composition and flue gas temperature as well as the deposit morphology, related to the flue gas flow pattern, on the mechanisms and corrosion rates. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Damage distribution and remnant life assessment of a super-heater outlet header used for long time

Energy Technology Data Exchange (ETDEWEB)

Hiroyuki, Okamura [Science Univ. of Tokyo (Japan); Ryuichi, Ohotani [Kyoto Univ. (Japan); Kazuya, Fujii [Japan Power Engineering and Inspection Corp., Tokyo (Japan); Masashi, Nakashiro; Fumio, Takemasa; Hideo, Umaki; Tomiyasu, Masumura [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

1998-11-01

This paper presents the results of investigation on evaluating damage distribution to base metals and welded joints in the thickness direction and evaluate damage on ligaments. Thick wall tested sample was the superheater outlet header component long term serviced in high pressure and temperature condition in thermal power plant. The simulate unused steel of component material was made from sample by suitable heat treatment, and the extent of damage was assessed based on a comparison of nondestructive and destructive test results between simulate unused and aged samples. Damage evaluation was also made by FEM structural stress analysis. (orig./MM)
Dynamic performances of wet turbine and steam-separator-superheater and their mathematical simulation as objects of temperature control

International Nuclear Information System (INIS)

Golovach, E.A.

1985-01-01

A mathematical model of a turbine and steam-separator-superheater (SSS) as applied to solution of the tasks of steam temperature regulaton after SSS has been developed. SSS as objects of steam temperature control are considerably less inertial, than intermediate superheaters (IS) of power units in thermal power plants, since for typical SSS and IS considered the duration of transition process according to steam temperature after SSS is 5-10 times loweA than for IS
Soft Sensor for Oxide Scales on the Steam Side of Superheater Tubes under Uneven Circumferential Load

Directory of Open Access Journals (Sweden)

Qing Wei Li

2015-01-01

Full Text Available A soft sensor for oxide scales on the steam side of superheater tubes of utility boiler under uneven circumferential loading is proposed for the first time. First finite volume method is employed to simulate oxide scales growth temperature on the steam side of superheater tube. Then appropriate time and spatial intervals are selected to calculate oxide scales thickness along the circumferential direction. On the basis of the oxide scale thickness, the stress of oxide scales is calculated by the finite element method. At last, the oxide scale thickness and stress sensors are established on support vector machine (SMV optimized by particle swarm optimization (PSO with time and circumferential angles as inputs and oxide scale thickness and stress as outputs. Temperature and stress calculation methods are validated by the operation data and experimental data, respectively. The soft sensor is applied to the superheater tubes of some power plant. Results show that the soft sensor can give enough accurate results for oxide scale thickness and stress in reasonable time. The forecasting model provides a convenient way for the research of the oxide scale failure.
A steam superheater exchanger provided with two coaxial casings and an horizontal axis

International Nuclear Information System (INIS)

Marjollet, Jacques; Palacio, Gerard; Tondeur, Gerard.

1976-01-01

This invention concerns the general lay-out of an horizontal axis separator-superheater for supplying steam to a high power turbine, particularly for a nuclear power station. The invention significantly reduces the length of the pipework connecting the superheated steam outlet and its inlet to the turbine. For this, the outer casing is provided with a coaxial internal annular sleeve in which are housed, one above the other, the separator and the bundle of superheater tubes through which circulates the water emulsion to be separated and steam to be superheated. At the end of its treatment, the superheated steam spreads out in the space between the sleeve and the outer casing from whence it can be drawn off at any point of its periphery, thus making it possible to choose an extraction point as near as possible to the inlet of the turbine to be fed [fr
Degradation of superheater tubes made of austenitic T321H steel after long term service

Energy Technology Data Exchange (ETDEWEB)

Hernas, Adam [Silesian Technical Univ., Katowice (Poland). Faculty of Material Science; Augustyniak, Boleslaw; Chmielewski, Marek [Gdansk Univ. of Technology (Poland). Mechanical Dept.; Sablik, M.J. [Applied Magnetic and Physical Modeling, LLC, San Antonio, TX (United States)

2010-07-01

There are presented results of complementary tests performed for the evaluation of creep damage in austenitic steel grade T321H exploited over 200,000 hours in the secondary superheater part of a power plant boiler. The following techniques have been applied: SEM microscopy, X-ray diffraction, tensile tests, hardness measurements and novel eddy current inspection. The novel eddy current inspection is proposed as a non-destructive method of estimating the creep damage stage of austenite steel boiler tubes after long-term service in power plants. We compare the results provided by the different techniques and discuss the correlations and also point out the problems which need to be addressed in order to elaborate the remaining life assessment of austenitic boiler tubes. (orig.)
Probabilistic approach to determining the optimum replacement of a superheater stage in 680 MW coal-fired boiler

Energy Technology Data Exchange (ETDEWEB)

Bos, Robert; Star, Ruud van der [Nuon Power Generation, Amsterdam (Netherlands)

2009-07-01

The boiler of the NUON power plant HW08 that went into operation in 1993 is designed as Benson boiler and mainly fired with hard coal. A creep-related tube failure occurred in the tertiary superheater that had been due to increased wall temperature caused by steam side formation of oxide layers. The theoretical lifetime of the components was calculated with the aid of the results of steam side oxide measurements and condition evaluation of the tertiary superheater with the aid of tube samples. The objective is to establish an operation and maintenance schedule for the desired operating lifetime of 300,000 hours. (orig.)

Improved superheater tubing material - Ti and Nb bearing austenitic steel

International Nuclear Information System (INIS)

Kinoshita, K.; Mimino, T.; Minegishi, I.

1975-01-01

A newly developed 18 Cr-8 Ni stainless steel modified with small amounts of Ti and Nb has considerably high stress-rupture strength and is considered to be suitable for superheater material for power boilers. Data for stress-rupture and creep for long times, the strength of welded joints, the changes of characteristics due to exposure to high temperatures, etc., are presented and discussed. Some investigations after trial services indicate that the experimental data are applicable to actual applications. (author)
CFD analysis of temperature imbalance in superheater/reheater region of tangentially coal-fired boiler

Science.gov (United States)

Zainudin, A. F.; Hasini, H.; Fadhil, S. S. A.

2017-10-01

This paper presents a CFD analysis of the flow, velocity and temperature distribution in a 700 MW tangentially coal-fired boiler operating in Malaysia. The main objective of the analysis is to gain insights on the occurrences in the boiler so as to understand the inherent steam temperature imbalance problem. The results show that the root cause of the problem comes from the residual swirl in the horizontal pass. The deflection of the residual swirl due to the sudden reduction and expansion of the flow cross-sectional area causes velocity deviation between the left and right side of the boiler. This consequently results in flue gas temperature imbalance which has often caused tube leaks in the superheater/reheater region. Therefore, eliminating the residual swirl or restraining it from being diverted might help to alleviate the problem.
On possibility of application of the parallel-mixed type coolant flow scheme to NPP steam generators linked with superheaters

International Nuclear Information System (INIS)

Malkis, V.A.; Lokshin, V.A.

1983-01-01

Optimum distribution of the coolant straight-through flow between the superheater, evaporator and economizer is determined and the parallel-mixed type flow scheme is compared with other schemes. The calculations are performed for the 250 MW(e) steam generator for the WWER-1000 reactor unit the inlet and outlet primary coolant temperature of which is 324 and 290 deg C, respectively, while the feed water and saturation temperatures are 220 and 278.5 deg C, respectively. The rated superheating temperature is 300 deg C. The comparison of different schemes has been performed according to the average temperature head value at the steam-generator under the condition of equality as well as essential difference in the heat transfer coefficients in certain steam-generator sections. The calculations have shown that the use of parallel-mixed type flow permits to essentially increase the temperature head of the steam generator. At a constant heat transfer coefficient in all steam generator sections the highest temperature head is reached. At relative flow rates in the steam generator, economizer and evaporator equal to 6, 8 and 86%, respectively. The superheated steam generator temperature head in this case by 12% exceeds the temperature head of the WWER-1000 reactor unit wet steam generator. In case of heat transfer coefficient reduction in the superheater by a factor of three, the choice of the primary coolant, optimum distribution permits to maintain the steam generator temperature head at the level of the WWER-1000 reactor unit wet-steam steam generator. The use of the parallel-mixed type flow scheme permits to design a steam generator of slightly superheated steam for the parameters of the WWER-1000 unit
The creep life of superheater and reheater tubes under varying pressure conditions in operational boilers

International Nuclear Information System (INIS)

Mizen, D.C.; Plastow, B.

1975-01-01

The first of each manufacturer's 500 MW boilers supplied to the CEGB (Central Electricity Generating Board) have been subjected to an extensive programme of tests for performance optimization and safe operation. Around 250 thermocouples on superheater and reheater tubes have in each case been monitored as part of the exercise. The readings are corrected and used to compute creep rupture damage based on internationally agreed stress rupture data and a simple cumulative damage concept. Comparison of the design creep rupture life and the cumulative life consumed has in several applications been invaluable in influencing operating procedures and arranging tube modifications or replacements, so that loss of generation by creep rupture failure is minimized. (author)
Thermal load non-uniformity estimation for superheater tube bundle damage evaluation

Directory of Open Access Journals (Sweden)

Naď Martin

2018-01-01

Full Text Available Industrial boiler damage is a common phenomenon encountered in boiler operation which usually lasts several decades. Since boiler shutdown may be required because of localized failures, it is crucial to predict the most vulnerable parts. If damage occurs, it is necessary to perform root cause analysis and devise corrective measures (repairs, design modifications, etc.. Boiler tube bundles, such as those in superheaters, preheaters and reheaters, are the most exposed and often the most damaged boiler parts. Both short-term and long-term overheating are common causes of tube failures. In these cases, the design temperatures are exceeded, which often results in decrease of remaining creep life. Advanced models for damage evaluation require temperature history, which is available only in rare cases when it has been measured and recorded for the whole service life. However, in most cases it is necessary to estimate the temperature history from available operation history data (inlet and outlet pressures and temperatures etc.. The task may be very challenging because of the combination of complex flow behaviour in the flue gas domain and heat transfer phenomena. This paper focuses on estimating thermal load non-uniformity on superheater tubes via Computational Fluid Dynamics (CFD simulation of flue gas flow including heat transfer within the domain consisting of a furnace and a part of the first stage of the boiler.
Evaporator Superheat Control With One Temperature Sensor Using Qualitative System Knowledge

DEFF Research Database (Denmark)

Vinther, Kasper; Hillerup Lyhne, Casper; Baasch Sørensen, Erik

2012-01-01

This paper proposes a novel method for superheat control using only a single temperature sensor at the outlet of the evaporator, while eliminating the need for a pressure sensor. An inner loop controls the outlet temperature and an outer control loop provides a reference set point, which is based...... filling of the evaporator, with only one temperature sensor. No a priori model knowledge was used and it is anticipated that the method is applicable on a wide variety of refrigeration systems....
On-line Auto-Tuning of PI Control of the Superheat for a Supermarket Refrigeration System

DEFF Research Database (Denmark)

Yang, Zhenyu; Andersen, Casper; Izadi-Zamanabadi, Roozbeh

2011-01-01

An online PI auto-tuning method is proposed for superheat control for a type of supermarket refrigeration systems. The proposed procedure consists of three serial steps: Step-One uses one of the two proposed empirical methods, namely multi-step method and relay method, for modeling initialization...
High temperature corrosion investigations at AW2-bio. Final report; Biomass boiler

Energy Technology Data Exchange (ETDEWEB)

Borg, U.

2011-01-15

The measured corrosion rates in the test superheaters and ordinary superheaters of Avedoere 2 biomass boiler reveal that the corrosion rate increases with metal temperature and is significantly accelerated above steam temperatures of 540 deg. C. For the boiler with a live steam temperature of 540 deg. C, the measured corrosion rates in superheater 2 and 3 were up to 1mm pr. 10000 hours. It was observed that the flue gas temperature and heat flux had a significant effect on the corrosion rates through the surface metal temperature. Thus, the highest corrosion rates in the ordinary superheaters were not found at the position of the highest steam temperature in the outlet of superheater 3, but at the outlet of superheater 2. A steam temperature of approximately 580 deg. C at the outlet of one of the test superheater loops caused a tube fracture after a few months. A HVOF coating was applied to a section of superheater 2 and at a higher temperature in the test superheater loop. Analyses of the tube section after exposure showed that parts of the coating were not present and corrosion of the underlying TP347H FG was apparent. This indicates that the coating had spalled during operation. Furthermore, chlorine diffusion through the coating was observed causing attack at the coating-alloy interface. The project work has shown that it is not possible to increase the live steam temperature of the biomass fired boiler to more than 540 deg. C without a significant increase in superheater corrosion rates for the applied tube materials and coatings. (Author)
Can the lifetime of the superheater tubes be predicted according to the fuel analyses? Assessment from field and laboratory data

Energy Technology Data Exchange (ETDEWEB)

Salmenoja, K [Kvaerner Pulping Oy, Tampere (Finland)

1999-12-31

Lifetime of the superheaters in different power boilers is more or less still a mystery. This is especially true in firing biomass based fuels (biofuels), such as bark, forest residues, and straw. Due to the unhomogeneous nature of the biofuels, the lifetime of the superheaters may vary from case to case. Sometimes the lifetime is significantly shorter than originally expected, sometimes no corrosion even in the hottest tubes is observed. This is one of the main reasons why the boiler operators often demand for a better predictability on the corrosion resistance of the materials to avoid unscheduled shutdowns. (orig.) 9 refs.
Can the lifetime of the superheater tubes be predicted according to the fuel analyses? Assessment from field and laboratory data

Energy Technology Data Exchange (ETDEWEB)

Salmenoja, K. [Kvaerner Pulping Oy, Tampere (Finland)

1998-12-31

Lifetime of the superheaters in different power boilers is more or less still a mystery. This is especially true in firing biomass based fuels (biofuels), such as bark, forest residues, and straw. Due to the unhomogeneous nature of the biofuels, the lifetime of the superheaters may vary from case to case. Sometimes the lifetime is significantly shorter than originally expected, sometimes no corrosion even in the hottest tubes is observed. This is one of the main reasons why the boiler operators often demand for a better predictability on the corrosion resistance of the materials to avoid unscheduled shutdowns. (orig.) 9 refs.
Complementary Methods for the Characterization of Corrosion Products on a Plant-Exposed Superheater Tube

DEFF Research Database (Denmark)

Okoro, Sunday Chukwudi; Nießen, Frank; Villa, Matteo

2017-01-01

In this work, complex corrosion products on a superheater tube exposed to biomass firing were characterized by the complementary use of energy-dispersive synchrotron diffraction, electron microscopy, and energy-dispersive X-ray spectroscopy. Non-destructive synchrotron diffraction in transmission......-rich austenite phase to selective removal of Fe and Cr from the alloy, via a KCl-induced corrosion mechanism. Compositional variations were related to diffraction results and revealed a qualitative influence of the spinel cation concentration on the observed diffraction lines.......In this work, complex corrosion products on a superheater tube exposed to biomass firing were characterized by the complementary use of energy-dispersive synchrotron diffraction, electron microscopy, and energy-dispersive X-ray spectroscopy. Non-destructive synchrotron diffraction in transmission...... geometry measuring with a small gauge volume from the sample surface through the corrosion product allowed depth-resolved phase identification and revealed the presence of (Fe,Cr)2O3 and FeCr2O4. This was supplemented by microstructural and elemental analysis correlating the additional presence of a Ni...
Premature failure of dissimilar metal weld joint at intermediate temperature superheater tube

OpenAIRE

Al Hajri, Mohammed; Malik, Anees U.; Meroufel, Abdelkader; Al-Muaili, Fahd

2015-01-01

Dissimilar metal weld (DMW) joint between alloyed steel (AS) and stainless steel (SS) failed at one of intermediate temperature superheater (ITSH) tube in steam/power generation plant boiler. The premature failure was detected after a relatively short time of operation (8 years) where the crack propagated circumferentially from AS side through the ITSH tube. Apart from physical examination, microstructural studies based on optical microscopy, SEM and EDX analysis were performed. The results o...
Evaluation report on CCTF Core-I reflood tests Cl-2 (Run 11) and Cl-3 (Run 12)

International Nuclear Information System (INIS)

Akimoto, Hajime; Murao, Yoshio

1983-06-01

In order to clarify the effect of the initial superheat of the downcomer wall on the system and the core cooling behaviors during the reflood phase of a PWR-LOCA, two tests were performed with the Cylindrical Core Test Facility (CCTF). One is the superheated wall test (test Cl-2) with the initial superheat of 79K, as in the actual PWR, and the other is the saturated wall test (test Cl-3) without any initial superheat. Through the comparisons of the test results from these two tests, the following conclusions were obtained. (1) The initial superheat of the downcomer wall resulted in the lower downcomer water head as observed in our separate-effect tests for the downcomer water head. (2) The superheat also caused the core inlet subcooling to be decreased, and led to the lower core water head. (3) The mass flow rate through the intact loop was reduced only by 4% by the initial superheat of the downcomer wall because the core water head was reduced as well as the downcomer water head. Whereas the mass flow rate through the broken loop was increased because of the increased pressure drop through the broken cold leg. (4) The difference of the core inlet mass flow rate was small between the superheated and the saturated wall tests. It can be considered that small difference of the core inlet mass flow rate results from the compensation of the decreased mass flow rate through the intact loops by the increased mass flow rate through the broken loop. (5) The main discrepancies of the core cooling and the carry-over behaviors between two CCTF tests, were consistent with those observed in the parametric tests for the core inlet subcooling of the FLECHT LOW FLOODING TEST series. (author)
High temperature (salt melt) corrosion tests with ceramic-coated steel

Energy Technology Data Exchange (ETDEWEB)

Schütz, Adelheid [University Bayreuth, Metals and Alloys, Ludwig-Thoma-Str. 36b, D-95447 Bayreuth (Germany); Günthner, Martin; Motz, Günter [University Bayreuth, Ceramic Materials Engineering, L.-Thoma-Str. 36b, D-95447 Bayreuth (Germany); Greißl, Oliver [EnBW Kraftwerke AG, Schelmenwasenstraße 13-15, D-70567 Stuttgart (Germany); Glatzel, Uwe, E-mail: uwe.glatzel@uni-bayreuth.de [University Bayreuth, Metals and Alloys, Ludwig-Thoma-Str. 36b, D-95447 Bayreuth (Germany)

2015-06-01

Thermal recycling of refuse in waste-to-energy plants reduces the problems connected to waste disposal, and is an alternative source of electric energy. However, the combustion process in waste incinerators results in a fast degradation of the steam-carrying superheater steel tubes by corrosive attack and abrasive wear. Higher firing temperatures are used to increase their efficiency but lead to higher corrosion rates. It is more economical to apply protective coatings on the superheater steel tubes than to replace the base material. In-situ tests were conducted in a waste-to-energy plant first in order to identify and quantify all involved corrosive elements. Laboratory scale experiments with salt melts were developed accordingly. The unprotected low-alloyed steel displayed substantial local corrosion. Corrosion was predominant along the grain boundaries of α-ferrite. The corrosion rate was further increased by FeCl{sub 3} and a mixture of HCL and FeCl{sub 3}. Coatings based on pre-ceramic polymers with specific filler particles were engineered to protect superheater tubes. Tests proved their suitability to protect low-alloYed steel tubes from corrosive attack under conditions typical for superheaterS in waste incinerators, rendering higher firing temperatures in waste-to-energy plants possible. - Highlights: • Corrosion wall thickness losses of 400 μm/2 weeks occurred in a waste incinerator. • Abrasion is a major problem on superheater tubes in waste incinerators. • Laboratory salt melt tests can simulate metal corrosion in waste incinerators. • Corrosion protection coatings for steel (temperature: max. 530 °C) were developed. • Higher steam temperatures are possible in WIs with the developed coatings.
Corrosion evaluation of heat recovery steam generator superheater tube in two methods of testing: Tafel polarization and electrochemical impedance spectroscopy (EIS)

Science.gov (United States)

Santoso, Rio Pudjidarma; Riastuti, Rini

2018-05-01

The purpose of this research is to evaluate the corrosion process which occurs on the water side of Heat Recovery Steam Generator (HRSG) superheater tube. The tube was 13CrMo44 and divided into 3 types of specimen: new tube, used tube (with oxide layer on surface), cleaned-used tube (without oxide layer on surface). The evaluation of corrosion parameters wasperformed using deaerated ultra-high purity water (boiler feed water) in two methods of testing: Tafel polarization and Electrochemical Impedance Spectroscopy (EIS). Tafel polarization was excellent as its capability to show the value of corrosion current and the corrosion rate explicitly, on the other hand, EIS was excellent as its capability to explain for corrosion mechanism on metal interface in detail. Both methods showed that the increase of electrolyte temperature from 25°C to 55°C would increase the corrosion rate with the mechanism of decreasing polarization resistance due to thinning out the passive film thickness and enlarge the area of reduction reaction of cathode. Magnetite oxide scale which is laid on the surface of used tube specimen shows protective nature to reduce the corrosion rate, and clear up this oxide would increase the corrosion rate back as new tube.
Determination of the concentration profile of chemical elements in superheater pipes

International Nuclear Information System (INIS)

Aldape U, F.; Aspiazu F, J.

1986-05-01

This work has for object to determine the profile of concentration of chemical elements at trace level in a superheater pipe of Thermoelectric Plants using the X-ray emission spectroscopy technique induced by protons coming from the Accelerator of the Nuclear Center. In the X-ray detection, a Si Li detector was used. The technique was chosen because it allows a multielemental analysis, of high sensitivity and precision. The results can help to understand the problems that are had in the change of flexibility or of corrosion. This will be from utility to the Federal Electricity Commission (CFE). (Author)
Failure Investigation of Radiant Platen Superheater Tube of Thermal Power Plant Boiler

Science.gov (United States)

Ghosh, D.; Ray, S.; Mandal, A.; Roy, H.

2015-04-01

This paper highlights a case study of typical premature failure of a radiant platen superheater tube of 210 MW thermal power plant boiler. Visual examination, dimensional measurement and chemical analysis, are conducted as part of the investigations. Apart from these, metallographic analysis and fractography are also conducted to ascertain the probable cause of failure. Finally it has been concluded that the premature failure of the super heater tube can be attributed to localized creep at high temperature. The corrective actions has also been suggested to avoid this type of failure in near future.
Production of A356 aluminum alloy wheels by thixo-forging combined with a low superheat casting process

Directory of Open Access Journals (Sweden)

Wang Shuncheng

2013-09-01

Full Text Available The A356 aluminum alloy wheels were produced by thixo-forging combined with a low superheat casting process. The as-cast microstructure, microstructure evolution during reheating and the mechanical properties of thixo-forged wheels made from the A356 aluminum alloy were studied. The results show that the A356 aluminum alloy round billet with fine, uniform and non-dendritic grains can be obtained when the melt is cast at 635 篊. When the round billet is reheated at 600 篊 for 60 min, the non-dendritic grains are changed into spherical ones and the round billet can be easily thixo-forged into wheels. The tensile strength, yield strength and elongation of the thixo-forged wheels with T6 heat treatment are 327.6 MPa, 228.3 MPa and 7.8%, respectively, which are higher than those of a cast wheel. It is suggested that the thixo-forging combined with the low superheat casting process is an effective technique to produce aluminum alloy wheels with high mechanical properties.
Study on superheat of TiAl melt during cold crucible levitation melting. TiAl no cold crucible levitation yokai ni okeru yoto kanetsudo no kenkyu

Energy Technology Data Exchange (ETDEWEB)

Miwa, K.; Kobayashi, K.; Ninomiya, M. (Government Industrial Research Institute, Nagoya, Nagoya (Japan))

1992-06-20

Investigations were given on effects of test sample weights and sample positions in cold crucibles on superheat of melts when the intermetallic compound TiAl is melted using cold crucible levitation melting process, one of noncontaminated melting processes. The cold crucibles used in the experiment are a water-cooled copper crucible with an inner diameter of 42 mm and a length of 140 mm, into which a column-like ingot sample with an outer diameter of 32 mm (Al containing Ti at 33.5% by mass) was put and melted using the levitation melting. Comparisons and discussions were given on the relationship between sample weights and melt temperatures, the relationship between positions of the inserted samples and melt temperatures, and the state of contamination at melting of casts obtained from the melts resulted from the levitation melting and high-frequency melting poured into respective ceramic dies. Elevating the superheat temperature of the melts requires optimizing the sample weights and positions. Melt temperatures were measured using a radiation thermometer and a thermocouple, and the respective measured values were compared. 7 refs., 4 figs., 1 tab.
Testing Header Component of Electricity Power Industry Boiler

International Nuclear Information System (INIS)

Soedardjo, S.A; Andryansyah, B; Artahari, Dewi; Natsir, Muhammad; Triyadi, Ari; Farokhi

2000-01-01

Testing of header component of Suralaya Unit II electricity power by replication method has been carried out. That header component is cross over pipe which interconnection between Primary and Superheater Outlet Header Secondary Superheater Outlet Header with the operation time over 14 years. The main composition of cross over pipe is 2 1/4 Cr 1 Mo or frequently specified as ferritique steel. The replication testing shown that the damage classification on those cross over pipe in A class based on failure classification from Neubauer and Wedel. Simple calculation in favor of cross over pipe remaining lifetime is about 16.5 years moreover

Review of Development Status of Nuclear Superheat; Expose sur l'etat actuel des travaux concernant la surchauffe nucleaire; Obzor razrabotki voprosa o yadernykh peregrevatelyakh; Estudio de los progresos realizados en niateria de sobrecalentamiento nuclear

Energy Technology Data Exchange (ETDEWEB)

Imhoff, D. H.; Pennington, R. T. [General Electric Company, San Jose, CA (United States)

1963-10-15

fuel irradiation performance, in-pile and out-of-pile uniform and localized corrosion evaluations, results from thermal superheat critical experiments, results from experimental heat-transfer testing and a brief appraisal of the economic incentives of the separate superheat reactor, integral superheat reactor, and mixed-spectrum superheat reactor design studies. (b) A brief description is given of the USAEC-Sponsored ESADA-VESR nuclear superheat fuel development programme. The development tasks, the initial core superheat fuel-element design, the range of experimental variables, and the expected results for the three-year fuel development programme are discussed. (author [French] Depuis 1959, la Societe General Electric s'occupe activement de mettre au point la surchauffe nucleaire dans les reacteurs ralentis a l'eau ordinaire. A cette epoque, le ''Superheat Advance Demonstration Experiment'' (SADE), finance par la societe, a permis d'obtenir, pour la premiere fois aux Etats-Unis, de la vapeur surchauffee par un dispositif nucleaire. Les auteurs du memoire font le point de la situation actuelle concernant la surchauffe nucleaire. Ils decrivent, dans une premiere partie, les trois principales installations de surchauffe nucleaire utilisees par la General Electric et, dans la seconde, les deux principaux programmes de recherches sur la surchauffe ainsi que les resultats les plus importants obtenus jusqu'ici dans ce domaine. 1. Principales installations pour les experiences de surchauffe: a) Breve description du SADE utilise dans le reacteur a eau bouillante de Vallecitos (VBWR), avec tableaux des conditions dans lesquelles se deroulent les experiences, et des elements combustibles irradies pendant la periode comprise entre mai 1959 et juin 1962; puis examen critique des resultats les plus importants ainsi obtenus. b) Breve description de l' ''Expanded Superheat Advance Demonstration Experiment'' (E-SADE) installe dans le reacteur de Vallecitos, avec tableaux des
Stress corrosion cracking in superheater and reheater austenitic tubing

Energy Technology Data Exchange (ETDEWEB)

Dooley, R. Barry [Structural Integrity Associates, Inc., Charlotte, NC (United States); Bursik, Albert [PowerPlant Chemistry GmbH, Neulussheim (Germany)

2011-02-15

University 101 courses are typically designed to help incoming first-year undergraduate students to adjust to the university, develop a better understanding of the college environment, and acquire essential academic success skills. Why are we offering a special Boiler and HRSG Tube Failures PPChem 101? The answer is simple, yet very conclusive: - There is a lack of knowledge on the identification of tube failure mechanisms and for the implementation of adequate counteractions in many power plants, particularly at industrial power and steam generators. - There is a lack of knowledge to prevent repeat tube failures. The vast majority of BTF/HTF have been, and continue to be, repeat failures. It is hoped that the information about the failure mechanisms of BTF supplied in this course will help to put plant engineers and chemists on the right track. The major goal of this course is the avoidance of repeat BTF. This eights lesson is focused on Stress Corrosion Cracking in Superheater and Reheater Austenitic Tubing. (orig.)
Microscopical investigation of steamside oxide on X20CrMoV121 superheater tubes

DEFF Research Database (Denmark)

Montgomery, Melanie; Hansson, Anette Nørgaard; Jensen, Søren A.

2011-01-01

X20CrMoV121 is a 12%Cr martensitic steel which has been used in power plants in Europe for many decades. Superheater tubes exposed for various durations up to 135,000 hours in power plants in Denmark at steam temperatures varying from 450 to 575°C were investigated. Light optical and scanning ele...... electron microscopy was used to investigate steamside oxide morphologies. At all temperatures there is a double layered oxide, however, the inner:outer oxide thickness is not always equal. At the lower steam temperature range of...
Effect of reinforcement amount, mold temperature, superheat, and mold thickness on fluidity of in-situ Al-Mg2Si composites

Directory of Open Access Journals (Sweden)

Reza Vatankhah Barenji

2018-01-01

Full Text Available In the present study, the effects of mold temperature, superheat, mold thickness, and Mg2Si amount on the fluidity of the Al-Mg2Si as-cast in-situ composites were investigated using the mathematical models. Composites with different amounts of Mg2Si were fabricated, and the fluidity and microstructure of each were then analyzed. For this purpose, the experiments were designed using a central composite rotatable design, and the relationship between parameters and fluidity were developed using the response surface method. In addition, optical and scanning electron microscopes were used for microstructural observation. The ANOVA shows that the mathematical models can predict the fluidity accurately. The results show that by increasing the mold temperature from 25 °C to 200 °C, superheat from 50 °C to 250 °C, and thickness from 3 mm to 12 mm, the fluidity of the composites decreases, where the mold thickness is more effective than other factors. In addition, the higher amounts of Mg2Si in the range from 15wt.% to 25wt.% lead to the lower fluidity of the composites. For example, when the mold temperature, superheat, and thickness are respectively 100 °C, 150 °C, and 7 mm, the fluidity length is changed in the range of 11.9 cm to 15.3 cm. By increasing the amount of Mg2Si, the morphology of the primary Mg2Si becomes irregular and the size of primary Mg2Si is increased. Moreover, the change of solidification mode from skin to pasty mode is the most noticeable microstructural effect on the fluidity.
Influence of surface roughness and melt superheat on HDA process to form a tritium permeation barrier on RAFM steel

Energy Technology Data Exchange (ETDEWEB)

Purushothaman, J. [B.S. Abdur Rahman University, Chennai 600048 (India); MTD, MMG, IGCAR, Kalpakkam 603102 (India); Ramaseshan, R., E-mail: seshan@igcar.gov.in [TFCS, SND, MSG, IGCAR, Kalpakkam 603102 (India); Albert, S.K. [MTD, MMG, IGCAR, Kalpakkam 603102 (India); Rajendran, R. [B.S. Abdur Rahman University, Chennai 600048 (India); Gowrishankar, N. [IP Rings Ltd., Maraimalainagar, Chennai 603209 (India); Ramasubbu, V. [MTD, MMG, IGCAR, Kalpakkam 603102 (India); Murugesan, S.; Dasgupta, Arup [PMG, MMG, IGCAR, Kalpakkam 603102 (India); Jayakumar, T. [MTD, MMG, IGCAR, Kalpakkam 603102 (India)

2015-12-15

Highlights: • Surface modified RAFMS samples were subjected to HDA and thermal oxidation. • Sample modified by SB process showed better coating and interface morphology. • Aluminized samples at 740 °C for 2 min showed Fe{sub 2}Al{sub 9}Si{sub 2} intermetallic phase. • Oxidized samples showed Fe{sub 2}Al{sub 8}Si, Fe{sub 2}Al{sub 3}Si{sub 3} and Fe{sub 3}Al{sub 2}Si{sub 3} intermetallic phases. • A uniform permeation barrier Al{sub 2}O{sub 3} was formed on the coating of oxidized HDA samples. - Abstract: The most optimal candidate material for fabrication of Test Blanket Module (TBM) in the installation of ITER and future fusion reactors is Reduced Activation Ferritic Martensitic (RAFM) steel, yet one of the major challenges that need to be addressed with RAFM is minimizing the loss of tritium in a reactor environment through the formation of tritium permeation barrier. One of the most promising methods for the tritium permeation barrier is through duplex coating with Al{sub 2}O{sub 3}/Fe–Al which is well known to reduce tritium permeation rate by several orders of magnitude. The present work aims to form an alumina layer on RAFM steel by a two-step method, which consists of (i) Hot Dip Aluminizing (HDA) and (ii) conversion of Al into alumina by a subsequent oxidation process. In addition, the influence of surface roughness of the substrate, superheat condition of the Al alloy melt and its composition on microstructural properties of coating before and after oxidation were investigated using OM, SEM–EDS, XRD, indentation micro hardness and scratch test. The experimental results confirmed the formation of alumina layer on RAFM steel after the HDA and oxidation process. Moreover, the surface roughness of the substrate, melt superheat of Al alloy and its composition are found to have a significant influence on the microstructure, thickness, micro-hardness, nature of intermetallic compounds formed and adhesion strength of the coating.
Premature failure of dissimilar metal weld joint at intermediate temperature superheater tube

Directory of Open Access Journals (Sweden)

Mohammed Al Hajri

2015-04-01

Full Text Available Dissimilar metal weld (DMW joint between alloyed steel (AS and stainless steel (SS failed at one of intermediate temperature superheater (ITSH tube in steam/power generation plant boiler. The premature failure was detected after a relatively short time of operation (8 years where the crack propagated circumferentially from AS side through the ITSH tube. Apart from physical examination, microstructural studies based on optical microscopy, SEM and EDX analysis were performed. The results of the investigation point out the limitation of Carbides precipitation at the alloyed steel/welding interface. This is synonym of creep stage I involvement in the failure of ITSH. Improper post-welding operation and bending moment are considered as root causes of the premature failure.
Acoustic emission analysis on tensile failure of steam-side oxide scales formed on T22 alloy superheater tubes

Energy Technology Data Exchange (ETDEWEB)

Huang, Jun-Lin; Zhou, Ke-Yi, E-mail: boiler@seu.edu.cn; Xu, Jian-Qun [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu Province (China); Wang, Xin-Meng; Tu, Yi-You [School of Materials Science and Engineering, Southeast University, Nanjing 210096, Jiangsu Province (China)

2014-07-28

Failure of steam-side oxide scales on boiler tubes can seriously influence the safety of coal-fired power plants. Uniaxial tensile tests employing acoustic emission (AE) monitoring were performed, in this work, to investigate the failure behavior of steam-side oxide scales on T22 alloy boiler superheater tubes. The characteristic frequency spectra of the captured AE signals were obtained by performing fast Fourier transform. Three distinct peak frequency bands, 100-170, 175-250, and 280-390 kHz, encountered in different testing stages were identified in the frequency spectra, which were confirmed to, respectively, correspond to substrate plastic deformation, oxide vertical cracking, and oxide spalling with the aid of scanning electronic microscopy observations, and can thus be used for distinguishing different oxide failure mechanisms. Finally, the critical cracking strain of the oxide scale and the interfacial shear strength of the oxide/substrate interface were estimated, which are the critical parameters urgently desired for modeling the failure behavior of steam-side oxide scales on boiler tubes of coal-fired power plants.
Acoustic emission analysis on tensile failure of steam-side oxide scales formed on T22 alloy superheater tubes

Science.gov (United States)

Huang, Jun-Lin; Zhou, Ke-Yi; Wang, Xin-Meng; Tu, Yi-You; Xu, Jian-Qun

2014-07-01

Failure of steam-side oxide scales on boiler tubes can seriously influence the safety of coal-fired power plants. Uniaxial tensile tests employing acoustic emission (AE) monitoring were performed, in this work, to investigate the failure behavior of steam-side oxide scales on T22 alloy boiler superheater tubes. The characteristic frequency spectra of the captured AE signals were obtained by performing fast Fourier transform. Three distinct peak frequency bands, 100-170, 175-250, and 280-390 kHz, encountered in different testing stages were identified in the frequency spectra, which were confirmed to, respectively, correspond to substrate plastic deformation, oxide vertical cracking, and oxide spalling with the aid of scanning electronic microscopy observations, and can thus be used for distinguishing different oxide failure mechanisms. Finally, the critical cracking strain of the oxide scale and the interfacial shear strength of the oxide/substrate interface were estimated, which are the critical parameters urgently desired for modeling the failure behavior of steam-side oxide scales on boiler tubes of coal-fired power plants.
Acoustic emission analysis on tensile failure of steam-side oxide scales formed on T22 alloy superheater tubes

International Nuclear Information System (INIS)

Huang, Jun-Lin; Zhou, Ke-Yi; Xu, Jian-Qun; Wang, Xin-Meng; Tu, Yi-You

2014-01-01

Failure of steam-side oxide scales on boiler tubes can seriously influence the safety of coal-fired power plants. Uniaxial tensile tests employing acoustic emission (AE) monitoring were performed, in this work, to investigate the failure behavior of steam-side oxide scales on T22 alloy boiler superheater tubes. The characteristic frequency spectra of the captured AE signals were obtained by performing fast Fourier transform. Three distinct peak frequency bands, 100-170, 175-250, and 280-390 kHz, encountered in different testing stages were identified in the frequency spectra, which were confirmed to, respectively, correspond to substrate plastic deformation, oxide vertical cracking, and oxide spalling with the aid of scanning electronic microscopy observations, and can thus be used for distinguishing different oxide failure mechanisms. Finally, the critical cracking strain of the oxide scale and the interfacial shear strength of the oxide/substrate interface were estimated, which are the critical parameters urgently desired for modeling the failure behavior of steam-side oxide scales on boiler tubes of coal-fired power plants.
Re-evaluation of superheat conditions postulated in NRC Information Notice 84-90

International Nuclear Information System (INIS)

Alsammarae, A.; Kruger, D.; Beutel, D.; Spisak, M.

1994-01-01

Information Notice 84-90, ''Main Steam Line Break Effect on Environmental Qualification of Equipment,'' describes a potential problem regarding existing plant analyses and Equipment Qualification (EQ) related to a postulated Main Steam Line Break (MSLB) with releases of superheated stream. This notice states that certain methodologies for computing mass and energy releases for a postulated MSLB did not account for heat transfer from the steam generator tube bundles if they were uncovered. Due to this potential change in the original environmental analysis, the EQ of various components may not consider the thermal environment which could result from superheated steam. Subsequent technical assessments may determine that the existing qualification basis for equipment/components does not envelop the postulated superheat condition. Corrective actions need to be taken to demonstrate that the affected equipment is qualified
Investigation into Cause of High Temperature Failure of Boiler Superheater Tube

Science.gov (United States)

Ghosh, D.; Ray, S.; Roy, H.; Shukla, A. K.

2015-04-01

The failure of the boiler tubes occur due to various reasons like creep, fatigue, corrosion and erosion. This paper highlights a case study of typical premature failure of a final superheater tube of 210 MW thermal power plant boiler. Visual examination, dimensional measurement, chemical analysis, oxide scale thickness measurement, microstructural examination are conducted as part of the investigations. Apart from these investigations, sulfur print, Energy Dispersive spectroscopy (EDS) and X ray diffraction analysis (XRD) are also conducted to ascertain the probable cause of failure of final super heater tube. Finally it has been concluded that the premature failure of the super heater tube can be attributed to the combination of localized high tube metal temperature and loss of metal from the outer surface due to high temperature corrosion. The corrective actions have also been suggested to avoid this type of failure in near future.
Effects of Degree of Superheat on the Running Performance of an Organic Rankine Cycle (ORC Waste Heat Recovery System for Diesel Engines under Various Operating Conditions

Directory of Open Access Journals (Sweden)

Kai Yang

2014-04-01

Full Text Available This study analyzed the variation law of engine exhaust energy under various operating conditions to improve the thermal efficiency and fuel economy of diesel engines. An organic Rankine cycle (ORC waste heat recovery system with internal heat exchanger (IHE was designed to recover waste heat from the diesel engine exhaust. The zeotropic mixture R416A was used as the working fluid for the ORC. Three evaluation indexes were presented as follows: waste heat recovery efficiency (WHRE, engine thermal efficiency increasing ratio (ETEIR, and output energy density of working fluid (OEDWF. In terms of various operating conditions of the diesel engine, this study investigated the variation tendencies of the running performances of the ORC waste heat recovery system and the effects of the degree of superheat on the running performance of the ORC waste heat recovery system through theoretical calculations. The research findings showed that the net power output, WHRE, and ETEIR of the ORC waste heat recovery system reach their maxima when the degree of superheat is 40 K, engine speed is 2200 r/min, and engine torque is 1200 N·m. OEDWF gradually increases with the increase in the degree of superheat, which indicates that the required mass flow rate of R416A decreases for a certain net power output, thereby significantly decreasing the risk of environmental pollution.
Review about corrosion of superheaters tubes in biomass plants; Revision sobre la corrosion de tubos sobrecalentadores en plantas de biomasa

Energy Technology Data Exchange (ETDEWEB)

Berlanga-Labari, C.; Fernandez-Carrasquilla, J.

2006-07-01

The design of new biomass-fired power plants with increased steam temperature raises concerns of high-temperature corrosion. The high potassium and chlorine contents in many biomass, specially in wheat straw, are potentially harmful elements with regard to corrosion. Chlorine may cause accelerated corrosion resulting in increased oxidation, metal wastage, internal attack, void formations and loose non-adherent scales. The most severe corrosion problems in biomass-fired systems are expected to occur due to Cl-rich deposits formed on superheater tubes. In the first part of this revision the corrosion mechanism proposed are described in function of the conditions and compounds involved. The second part is focused on the behaviour of the materials tested so far in the boiler and in the laboratory. First the traditional commercial alloys are studied and secondly the new alloys and the coasting. (Author). 102 refs.
Mitigating the Risk of Stress Corrosion of Austenitic Stainless Steels in Advanced Gas Cooled Reactor Boilers

International Nuclear Information System (INIS)

Bull, A.; Owen, J.; Quirk, G.; G, Lewis; Rudge, A.; Woolsey, I.S.

2012-09-01

corrosion damage to the Type 316 superheater sections in the affected units an extensive programme of test work and plant modelling has been undertaken over a number of years. This has involved stress corrosion test work using full scale plant boiler simulations under a variety of feedwater chemistry conditions for both helical and serpentine boilers. Data from these investigations has then been used to construct models of the damage process that allow the risk of tube leaks due to stress corrosion cracking to be assessed. These models use plant feedwater chemistry and thermal-hydraulic data as inputs. The paper describes investigations of the risk of stress corrosion cracking in AGR boilers and the improvements in feedwater quality of the affected units to help mitigate the risk. (authors)
Investigation of thermodynamic cycle for generic 1200 MW{sub el} pressure channel reactor with nuclear steam superheat

Energy Technology Data Exchange (ETDEWEB)

Vincze, A.; Sidawi, K.; Abdullah, R.; Baldock, M.; Saltanov, E.; Pioro, I., E-mail: andrei.vincze@uoit.net, E-mail: khalil.sidawi@uoit.net, E-mail: rand.abdullah@uoit.net, E-mail: matthew.baldock@uoit.net, E-mail: eugene.saltanov@uoit.ca, E-mail: igor.pioro@uoit.ca [Univ. of Ontario Inst. of Tech., Oshawa, ON (Canada)

2014-07-01

Current Nuclear Power Plants (NPPs) play a significant role in energy production around the world. All NPPs operating today employ a Rankine steam cycle for the conversion of thermal power to electricity. This paper will examine the steam cycle arrangement an experimental pressure channel reactor using Nuclear Steam Superheat (NSS) and compare it to two advanced reactor designs, the Advanced CANDU Reactor 1000 (ACR-1000) and the Advanced Boiling Water Reactor (ABWR) designs. The thermodynamic cycle layout and thermal efficiencies of the three reactor types will be discussed. (author)
Experiences with high temperature corrosion at straw‐firing power plants in Denmark

DEFF Research Database (Denmark)

Montgomery, Melanie; Jensen, S. A.; Borg, U.

2011-01-01

to enable better lifetime prediction of vulnerable components in straw‐firing plants since the corrosion rates are so much faster than in coal firing plants. Therefore, there are continued investigations in recently commissioned plants with test tubes installed into actual superheaters. In addition...... temperature is measured on the specific tube loops where there are test tube sections. Thus a corrosion rate can be coupled to a temperature histogram. This is important since although a superheater has a defined steam outlet temperature, there is variation in the tube bundle due to variations of heat flux...
Long term testing of materials for tube shielding, stage 2; Laangtidsprovning av tubskyddsmaterial, etapp 2

Energy Technology Data Exchange (ETDEWEB)

Norling, Rikard; Hjoernhede, Anders; Mattsson, Mattias

2012-02-15

Circulating Fluidized Bed (CFB) boilers are commonly used for combustion of biomass and are used to some extent for Waste-to-Energy (WtE) plants as well. The superheaters of the latter are for obvious reasons more prone to suffer from high temperature corrosion caused by the corrosive species in the fuel, mainly chlorides. Frequently the final (hottest) superheater is positioned in the loop seal, where the circulating bed material is returned to the furnace after being separated from the flue gas by a cyclone. The environment in the loop seal is relatively free of chlorides, since these primarily follow the flue gas into the convection pass. Hence, higher steam temperature can be allowed without excessive damage to the final superheater. On the other hand the superheaters, which are located in the convection pass, are more exposed to the corrosive species of the flue gas. Further, they are eroded by particles entrained in the gas flow. Particles and condensing gaseous species are to a large extent deposited on the superheaters, which limits the heat transfer and promotes corrosion. The deposits are regularly removed e.g. by soot blowers. The pressurized steam from soot blowers causes additional erosion damage to that caused by entrained particles. It shall be noted that the actual damage is caused by a combined mechanism of erosion and corrosion denoted erosion-corrosion, which usually results in dramatically accelerated wear. To avoid excessive erosion damage on the superheater tubes the first tube row of each bundle is protected by tube shielding. In its simplest form the shields are made from a steel sheet that has been bent into a semi-circular half-cylinder shell. These shields are attached onto the wind-side of the tubes by hangers. A typical material for tube shielding is the austenitic high temperature resistant stainless steel 253MA. Life of tube shielding depends on numerous factors such as boiler design, superheater location, fuel and operating
Field test corrosion experiments in Denmark with biomass fuels Part I Straw firing

DEFF Research Database (Denmark)

Montgomery, Melanie; Karlsson, A; Larsen, OH

2002-01-01

plants. The type of corrosion attack can be directly ascribed to the composition of the deposit and the metal surface temperature. A series of field tests have been undertaken in the various straw-fired power plants in Denmark, namely Masnedø, Rudkøbing and Ensted. Three types of exposure were undertaken......In Denmark, straw and other types of biomass are used for generating energy in power plants. Straw has the advantage that it is a "carbon dioxide neutral fuel" and therefore environmentally acceptable. Straw combustion is associated with corrosion problems which are not encountered in coal-fired...... to investigate corrosion: a) the exposure of metal rings on water/air cooled probes, b) the exposure of test tubes in a test superheater, and c) the exposure of test tubes in existing superheaters. Thus both austenitic steels and ferritic steels were exposed in the steam temperature range of 450-600°C...
Effects of Different Fuel Specifications and Operation Conditions on the Performance of Coated and Uncoated Superheater Tubes in Two Different Biomass-Fired Boilers

DEFF Research Database (Denmark)

Wu, Duoli; Dahl, Kristian V.; Madsen, Jesper L.

2018-01-01

Fireside corrosionis a serious concern in biomass firing powerplants such that the efficiency of boilers is limited by high temperature corrosion. Application of protective coatings on superheater tubes is a possible solution to combat fireside corrosion. The current study investigates the corros......Fireside corrosionis a serious concern in biomass firing powerplants such that the efficiency of boilers is limited by high temperature corrosion. Application of protective coatings on superheater tubes is a possible solution to combat fireside corrosion. The current study investigates...... the corrosion performance of coated tubes compared to uncoated Esshete 1250 and TP347H tubes, which were exposed in two different biomass-fired boilers for one year. Data on the fuel used, temperature of the boilers, and temperature fluctuations are compared for the two boilers, and how these factors influence...... deposit formation, corrosion, and the stability of the coatings is discussed. The coatings (Ni and Ni2Al3) showed protective behavior ina wood-fired plant where the outlet steam temperature was 520 °C. However, at the plant that fired straw with an outlet steam temperature of 540 °C and where severe...
Coal Ash Corrosion Resistant Materials Testing

Energy Technology Data Exchange (ETDEWEB)

D. K. McDonald; P. L. Daniel; D. J. DeVault

2007-12-31

In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a moderate alkali content (0.2% sodium equivalents), thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that aggressive alkali sulfate constituents were present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. Test Section A was removed in November 2001 after about 24 months of service at the desired steam temperature set point, with about 15.5 months of exposure at full temperature. A progress report, issued in October 2002, was written to document the performance of the candidate alloys in that test section. The evaluation described the condition of each tube sample after exposure. It involved a determination of the rate of wall thickness loss for these samples. In cases where there was more than one sample of a candidate material in the test section, an assessment was made of the performance of the alloy as a function of temperature. Test Sections B and C were examined during the November 2001 outage, and it was decided that

The Heat Flux Analysis in an Annulus Narrows Gap With Initial Temperature Variations Using HeaTiNG-01 Test Section

International Nuclear Information System (INIS)

Mulya Juarsa; Efrizon Umar; Andhang Widi Harto

2009-01-01

An experiment to understand the complexity of boiling phenomena on a narrow gap, which has occurs in severe accident at TMI-2 NPP is necessary to be done in aimed to increase the understanding of accident management. The goal of research is to obtain a heat flux and critical heat flux (CHF) value during boiling heat transfer process in a narrow gap annulus. The method of research is experimental using HeaTiNG-01 test section. The experiment has been done with heating-up heated rod until a certain initial temperature, for this experiment, three initial temperature variations was decided at 650°C, 750°C dan 850°C. Then, a cooling process in heated rod by saturated water was recorded based on temperature data changes. Temperature data was used to calculate a value of heat flux and wall superheat temperature, until the results could be defined in boiling curve. The result of this research shows that, although the initial temperature of heated rod was different, the value of CHF is almost similar with CHF average 253.7 kW/m 2 with the changes of only 4.7%. The event of boiling in a narrow gap is not included pool boiling category based on the comparison of film boiling area of the experiment to Bromley correlations. (author)
Combustor Section Acoustic Test

National Research Council Canada - National Science Library

Swanson, Andrew

2003-01-01

.... Following successful coupon and subelement tests on laser welding of Inco 625 heat exchangers, a full-scale scramjet flowpath section was fabricated to more realistically demonstrate the viability of the design concept...
Vivitron dead section pumping tests

International Nuclear Information System (INIS)

Heugel, J.; Bayet, J.P.; Brandt, C.; Delhomme, C.; Krieg, C.; Kustner, F.; Meiss, R.; Riehl, R.; Roth, C.; Schlewer, B.; Six, P.; Weber, A.

1990-10-01

Pumping tests have been conducted on a simulated accelerator dead section. The behavior of different pump types are compared and analyzed. Vacuum conditions to be expected in the Vivitron are reached and several parameters are verified. Selection of a pump for the Vivitron dead section is confirmed
Compressor Calorimeter Test of R-410A Alternatives R-32, DR-5, and L-41a

Energy Technology Data Exchange (ETDEWEB)

Shrestha, Som S [ORNL; Mahderekal, Isaac [ORNL; Sharma, Vishaldeep [ORNL; Abdelaziz, Omar [ORNL

2013-02-01

As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares performance of alternative refrigerants R32, DR-5, and L-41A to that of refrigerant R-410A (baseline) in a scroll compressor designed for air-conditioning and heat pump applications. Compressor calorimeter tests were performed to evaluate the performance of the lower-GWP alternative refrigerants in place of the common refrigerant R-410A in a 36,000 Btu/hr compressor calorimeter using a compressor having a nominal rated capacity of 21,300 Btu/hr. Tests were conducted over a suction dew point temperature range of 10 F to 55 F in 5 F increments and a discharge dew point temperature range of 70 F to 140 F in 10 F increments. All the tests were performed with 20 F superheat, 40 F superheat and 65 F suction temperature. A liquid subcooling level of 15 F was maintained for all the test conditions. The tests showed that performance of these three lower-GWP alternative refrigerants is comparable to that of R-410A. For the 20 F superheat and 15 F subcooling test conditions, EERs of R32, DR-5, and L-41A were 90% to 99%, 96% to 99%, and 94% to 101%, respectively, compared to that of R-410A. Similarly, cooling capacities of R32, DR-5, and L-41A were 98% to 103%, 92% to 96%, and 84% to 92%, respectively, compared to that of R-410A.
Failure Analysis and Magnetic Evaluation of Tertiary Superheater Tube Used in Gas-Fired Boiler

Science.gov (United States)

Mohapatra, J. N.; Patil, Sujay; Sah, Rameshwar; Krishna, P. C.; Eswarappa, B.

2018-02-01

Failure analysis was carried out on a prematurely failed tertiary superheater tube used in gas-fired boiler. The analysis includes a comparative study of visual examination, chemical composition, hardness and microstructure at failed region, adjacent and far to failure as well as on fresh tube. The chemistry was found matching to the standard specification, whereas the hardness was low in failed tube compared to the fish mouth opening region and the fresh tube. Microscopic examination of failed sample revealed the presence of spheroidal carbides of Cr and Mo predominantly along the grain boundaries. The primary cause of failure is found to be localized heating. Magnetic hysteresis loop (MHL) measurements were carried out to correlate the magnetic parameters with microstructure and mechanical properties to establish a possible non-destructive evaluation (NDE) for health monitoring of the tubes. The coercivity of the MHL showed a very good correlation with microstructure and mechanical properties deterioration enabling a possible NDE technique for the health monitoring of the tubes.
Design criteria and fabrication in-pile test section of HANARO fuel test loop

Energy Technology Data Exchange (ETDEWEB)

Kim, J. Y.

1997-10-01

Safety state fuel test loop will be equipped in HANARO to obtain the development and betterments of advanced fuel and materials through the irradiation tests. The objective of this study is to determine the design criteria and technical specification of in-pile test section and to specify the manufacturing requirements of in-pile test section. HANARO fuel test loop was designed to meet the CANDU and PWR fuel testing and in-pile section will be manufactured and installed in HANARO. The design criteria and technical specification of in-pile test section could be used the fuel and materials design with for irradiation testing IPS of HANARO fuel test loop. This results will become guidances for the planning and programming of irradiation testing. (author). 12 refs., tabs., figs.
Detection and Repair of Ligament Cracks in a 109mm Thick Superheater Outlet Header

International Nuclear Information System (INIS)

Day, Peter

2006-01-01

Conventional thermal power station boilers are constructed of drums and a series of headers which are interconnected with many hundreds of tubes. Typically feed water enters the boiler at about 250 deg C at a pressure of around 250 bar with steam outlet temperatures of 540 deg C and a pressure of 170 bar. Superheater outlet headers may be subjected to quite arduous conditions during service. Not only are they exposed to high pressure stresses but also to high thermal stresses due to varying thermal gradients through the section thickness particularly at start up and during two shift operation. The area that is exposed to the greatest thermal gradients is the narrow ligament that exists between the tube hole penetrations in the header bore. In the mid the 1980's industry wide surveys found cracking in a large percentage (25-50%) of headers after 15 years of service. Detection and sizing of ligament cracking and estimates of the rate of growth are therefore a major consideration especially in plant that is two shifted. In order to manage the risk both remote visual and ultrasonic inspection are performed during each major unit overhaul. Conclusion: Ultrasonic techniques used for this inspection need to be carefully evaluated with respect to their effectiveness. Conventional pulse echo is capable of detection but using for example a technique such as AS2207 level 1 will not show the defect size. Time of flight diffraction has shown itself to be effective in accurately sizing ligament cracking. However the complex geometry of header ligaments appears to cause a narrowing of the beam with the effect that crack tip responses can be concentrated at the centre of the ligament. Therefore great care needs to be taken during data interrogation because errors in sizing can occur. Wherever possible both 'B' and 'D' scan data should be collected. It appears that the greatest accuracy is obtained with respect to defect growth from the B scan image. With respect to the welding a
A Study of Aerodynamics in Kevlar-Wall Test Sections

OpenAIRE

Brown, Kenneth Alexander

2014-01-01

This study is undertaken to characterize the aerodynamic behavior of Kevlar-wall test sections and specifically those containing two-dimensional, lifting models. The performance of the Kevlar-wall test section can be evaluated against the standard of the hard-wall test section, which in the case of the Stability Wind Tunnel (SWT) at Virginia Tech can be alternately installed or replaced by the Kevlar-wall test section. As a first step towards the evaluation of the Kevlar-wall test section aer...
Calculation study of nonequilibrium post-CHF heat transfer in rod bundle test using modified RELAP5/MOD2

International Nuclear Information System (INIS)

Hassan, Y.A.

1987-01-01

To date there is only very limited data for non-equilibrium convective film boiling in rod bundle geometries. A recent nine (3 x 3) rod bundle post-critical-flux (CHF) test from the Lehigh University test facility was simulated using RELAP5/MOD2, to assess its capabilities in predicting the overall convective mechanisms in post-CHF heat transfer in rod bundle geometries. The code calculations were compared with experimental data. The code predicted low vapor superheats and void fraction oscillations. A new interfacial heat transfer between the droplet/steam resulted in a reasonable prediction of vapor superheats. A revised dispersed flow film boiling correlation which accounts for the enhancement of steam convective cooling by droplet-induced turbulence was incorporated in the code. Comparison with the data showed a fair agreement
Fireside corrosion and steamside oxidation of 9-12% Cr martensitic steels exposed for long term testing

DEFF Research Database (Denmark)

Montgomery, Melanie; Jensen, S. A.; Rasmussen, F.

2009-01-01

MoV121 and HCM12 for the 12% Cr steels. The test tubes were welded in as part of the existing final superheaters in actual plants and exposure has been conducted over a ten year period (1994-2005). Compared to the older steel types, T92 and HCM12 utilise tungsten to improve their creep strength. From......To obtain long term corrosion and steam oxidation data for the 9-12%Cr ferritic steels, test tube sections have been exposed in Amager 3 and Avedore 1 coal fired power plants in Denmark (formerly run by ENERGI E2). Thus direct comparisons can be made for T91 and T92 for the 9% Cr steels and X20Cr...... Avedore I testing, T91 and T92 can be compared for exposure times up to similar to 48 000 h exposure. From Amager 3 testing, X20, HCM12 and T92 were tested; T92 has been exposed for up to 31 000 h and X20 and HCM12 have had 84 500 h exposure. Tube sections were removed for various exposure durations...
Failure problems in superheater spacers of steam generators; Problematica de fallas en espaciadores de sobrecalentadores de generadores de vapor

Energy Technology Data Exchange (ETDEWEB)

Chacon Nava, Jose G; Martinez Villafane, Alberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Fuentes Samaniego, Raul [Universidad Autonoma de Nuevo Leon (Mexico); Mojica Calderon, Cecilio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1988-12-31

In this article the general aspects of the steam generator superheater fixed spacers failures are analyzed, emphasis is made on the influence several aspects such as the operation of the unit have, the appropriate execution of welds and the selection of binding materials. Likewise several recommendations are made to bring the failures to a minimum. [Espanol] En este articulo se analizan aspectos generales de fallas en espaciadores fijos de sobrecalentadores de generadores de vapor, y se hace hincapie en la influencia que tienen diversos aspectos tales como la operacion de la unidad, la adecuada ejecucion de soldaduras y la seleccion del material de aporte. Asimismo, se proponen algunas recomendaciones para reducir al minimo las fallas.
Pre-oxidation and its effect on reducing high-temperature corrosion of superheater tubes during biomass firing

DEFF Research Database (Denmark)

Okoro, Sunday Chukwudi; Kvisgaard, M.; Montgomery, Melanie

2017-01-01

Superheater tubes in biomass-fired power plants experience high corrosion rates due to condensation of corrosive alkali chloride-rich deposits. To explore the possibility of reducing the corrosion attack by the formation of an initial protective oxide layer, the corrosion resistance of pre......-oxidised Al and Ti-containing alloys (Kanthal APM and Nimonic 80A, respectively) was investigated under laboratory conditions mimicking biomass firing. The alloys were pre-oxidised at 900°C for 1 week. Afterwards, pre-oxidised samples, and virgin non-pre-oxidised samples as reference, were coated...... with a synthetic deposit of KCl and exposed at 560°C for 1 week to a gas mixture typical of biomass firing. Results show that pre-oxidation could hinder the corrosion attack; however, the relative success was different for the two alloys. While corrosion attack was observed on the pre-oxidised Kanthal APM, the pre...
Field test results for steam oxidation of TP347H FG - growth of inner oxide

DEFF Research Database (Denmark)

Montgomery, Melanie; Jianmin, Jia; Larsen, OH

2005-01-01

A series of field tests have been conducted with TP347H FG in test superheater loops in coal-fired and biomass fired boilers of steam pressure 256 and 91 bar respectively. The exposure times are from 3,500 to 30,000 hours and the temperature range is from 450-630¢XC. The morphology, composition...
Evaluation of materials' corrosion and chemistry issues for advanced gas cooled reactor steam generators using full scale plant simulations

International Nuclear Information System (INIS)

Woolsey, I.S.; Rudge, A.J.; Vincent, D.J.

1998-01-01

Advanced Gas Cooled Reactors (AGRS) employ once-through steam Generators of unique design to provide steam at approximately 530 degrees C and 155 bar to steam turbines of similar design to those of fossil plants. The steam generators are highly compact, and have either a serpentine or helical tube geometry. The tubes are heated on the outside by hot C0 2 gas, and steam is generated on the inside of the tubes. Each individual steam generator tube consists of a carbon steel feed and primary economiser section, a 9%Cr steel secondary economiser, evaporator and primary superheater, and a Type 316L austenitic stainless steel secondary superheater, all within a single tube pass. The multi-material nature of the individual tube passes, the need to maintain specific thermohydraulic conditions within the different material sections, and the difficulties of steam generator inspection and repair, have required extensive corrosion-chemistry test programmes to ensure waterside corrosion does not present a challenge to their integrity. A major part of these programmes has been the use of a full scale steam generator test facility capable of simulating all aspects of the waterside conditions which exist in the plant. This facility has been used to address a wide variety of possible plant drainage/degradation processes. These include; single- and two-phase flow accelerated corrosion of carbon steel, superheat margins requirements and the stress-corrosion behaviour of the austenitic superheaters, on-load corrosion of the evaporator materials, and iron transport and oxide deposition behaviour. The paper outlines a number of these, and indicates how they have been of value in helping to maintain reliable operation of the plant. (author)
Compressor Calorimeter Test of R-410A Alternative: R-32/134a Mixture Using a Scroll Compressor

Energy Technology Data Exchange (ETDEWEB)

Shrestha, Som S [ORNL; Sharma, Vishaldeep [ORNL; Abdelaziz, Omar [ORNL

2014-02-01

As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares the performance of lower-GWP alternative refrigerant R-32 + R-134a mixture, to that of refrigerant R-410A (baseline) in a scroll compressor designed for air-conditioning and heat pump applications. These comparisons were carried out via compressor calorimeter tests performed on a compressor designed for refrigerant R-410A and having a nominal rated capacity of 21,300 Btu/hr. Tests were conducted over a suction dew point temperature range of 10 F to 55 F in 5 F increments and a discharge dew point temperature range of 70 F to 140 F in 10 F increments. All the tests were performed with 20 F superheat, 40 F superheat, and 65 F suction temperature. A liquid subcooling level of 15 F was maintained for all the test conditions. The tests showed that the discharge temperature of the alternative refrigerant was higher than that of R-410A at all test conditions. Also, the energy efficiency ratio (EER) and cooling capacity of compressor using the alternative refrigerant were slightly lower in comparison to that of R-410A.
A computational approach for thermomechanical fatigue life prediction of dissimilarly welded superheater tubes

Energy Technology Data Exchange (ETDEWEB)

Krishnasamy, Ram-Kumar; Seifert, Thomas; Siegele, Dieter [Fraunhofer-Institut fuer Werkstoffmechanik (IWM), Freiburg im Breisgau (Germany)

2010-07-01

In this paper a computational approach for fatigue life prediction of dissimilarly welded superheater tubes is presented and applied to a dissimilar weld between tubes made of the nickel base alloy Alloy617 tube and the 12% chromium steel VM12. The approach comprises the calculation of the residual stresses in the welded tubes with a multi-pass dissimilar welding simulation, the relaxation of the residual stresses in a post weld heat treatment (PWHT) simulation and the fatigue life prediction using the remaining residual stresses as initial condition. A cyclic fiscoplasticity model is used to calculate the transient stresses and strains under thermocyclic service loadings. The fatigue life is predicted with a damage parameter which is based on fracture mechanics. The adjustable parameters of the model are determined based on LCF and TMF experiments. The simulations show, that the residual stresses that remain after PWHT further relax in the first loading cycles. The predicted fatigue lives depend on the residual stresses and, thus, on the choice of the loading cycle in which the damage parameter is evaluated. It the first loading cycle, where residual stresses are still present, is considered, lower fatigue lives are predicted compared to predictions considering loading cycles with relaxed residual stresses. (orig.)
Corrosion protection on superheaters of waste to energy plants. Experience with material and application; Korrosionsschutz im Ueberhitzerbereich. Erfahrungen mit Werkstoff und Applikation aus Qualitaetsbegleitungen

Energy Technology Data Exchange (ETDEWEB)

Schmidl, Werner; Herzog, Thomas; Magel, Gabi; Mueller, Wolfgang; Spiegel, Wolfgang [CheMin GmbH, Augsburg (Germany)

2011-07-01

Corrosion induced by chlorine at high temperatures and corrosion by salt melts sometimes cause severe risk and loss of operational availability in waste- and biomass-fired power plants. This corrosion very often affects the superheater. Due to high maintenance needs, several approaches to anti-corrosion coating have been developed. Nickel-based alloys such as alloy 625 are chosen to be applied as cladding or by thermal spraying. Operation periods have been considerably increased by these methods. But still there are some shortcomings in corrosion protection due to application and/or material. (orig.)
Determination of the concentration profile of chemical elements in superheater pipes; Determinacion del perfil de concentracion de elementos quimicos en tubos de sobrecalentadores

Energy Technology Data Exchange (ETDEWEB)

Aldape U, F; Aspiazu F, J [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

1986-05-15

This work has for object to determine the profile of concentration of chemical elements at trace level in a superheater pipe of Thermoelectric Plants using the X-ray emission spectroscopy technique induced by protons coming from the Accelerator of the Nuclear Center. In the X-ray detection, a Si Li detector was used. The technique was chosen because it allows a multielemental analysis, of high sensitivity and precision. The results can help to understand the problems that are had in the change of flexibility or of corrosion. This will be from utility to the Federal Electricity Commission (CFE). (Author)
The test section of the COSIMA blowdown test facility

International Nuclear Information System (INIS)

Bruederle, F.; Hain, K.

1980-08-01

The test section of the COSIMA blowdown test facility has been designed as a geometric analogy of the core of a pressurized water reactor for a shortened single fuel rod simulator. Its design and instrumentation together with the whole loop allow to simulate out of pile and trace by measurements the energy and hydraulic conditions arising in a blowdown. Special attention is being given in this report to one particular design problem: the number of load cycles up to incipient cracking of the test section as a pressure vessel containing hot water at high pressures and subjected to extreme rates of temperature variation in excess of 300 K/min. The methods of calculating cyclic loads as specified in the German Technical Rules for Boilers (TRD) have been supplemented in such a way that the number of load cycles up to incipient cracking may now be determined not only by the mean wall temperature, which is difficult to measure, but equally also well by the outer wall temperature, which is easy to measure precisely. (orig.) [de
Construction of In-core Structure Test Section in HENDEL, (1)

International Nuclear Information System (INIS)

Kunitomi, Kazuhiko; Inagaki, Yoshiyuki; Ioka, Ikuo; Kondoh, Yasuo; Nekoya, Shinichi; Miyamoto, Yoshiaki; Akisada, Toshihiro; Yamaguchi, Shigeru.

1988-01-01

An In-core Structure Test Section (T 2 ) in Helium Engineering Demonstration Loop (HENDEL) simulates a part of the core bottom structure with the same scale as that of a high temperature engineering test reactor (HTTR) designed in Japan Atomic Energy Research Institute. The design and construction of T 2 test section were started in March 1983, and completed in June 1986. The main objectives of the T 2 test section are to verify thermal-hydraulic performance and integrity of the core bottom structure. The report describes the general outline of T 2 test section, and experience gained from construction and preliminary test with regard to the simulated core bottom structure. (author)

Results of recent KROTOS FCI tests. Alumina vs. corium melts

Energy Technology Data Exchange (ETDEWEB)

Huhtiniemi, I.; Magallon, D.; Hohmann, H. [Commission of the European Communities, Ispra (Italy). Joint Research Center

1998-01-01

Recent results from KROTOS fuel-coolant interaction experiments are discussed. Five tests with alumina were performed under highly subcooled conditions, all of these tests resulted in spontaneous steam explosions. Additionally, four tests were performed at low subcooling to confirm, on one hand, the suppression of spontaneous steam explosions under such conditions and, on the other hand, that such a system is still triggerable using an external initiator. The other test parameters in these alumina tests included the melt superheat and the initial pressure. All the tests in the investigated superheat range (150 K - 750 K) produced a steam explosion and no evidence of the explosion suppression by the elevated initial pressure (in the limited range of 0.1 - 0.375 MPa) was observed in the alumina tests. The corium test series include a test with 3 kg of melt under both subcooled and near saturated conditions at ambient pressure. Two additional tests were performed with subcooled water; one test was performed at an elevated pressure of 0.2 MPa with 2.4 kg of melt and another test with 5.1 kg of melt at ambient pressure. None of these tests with corium produced a propagating energetic steam explosion. However, propagating low energy (about twice the energy of the trigger pulse) events were observed. All corium tests produced significantly higher water level swells during the mixing phase than the corresponding alumina tests. Present experimental evidence suggests that the water depletion in the mixing zone suppresses energetic steam explosions with corium melts at ambient pressure and in the present pour geometry. Processes that could produce such a difference in void generation are discussed. (author)
Phase identification and internal stress analysis of steamside oxides on superheater tubes by means of X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Pantleon, Karen; Montgomery, Melanie [Technical Univ. of Denmark, Lyngby (Denmark). Inst. of Manufacturing Engineering and Management

2005-05-01

For superheater tubes, the adherence of the inner steamside oxide is especially important as spallation of this oxide results in a) blockage of loops which cause insufficient steam flow through the superheaters and subsequently overheating and tube failure and b) spalled oxide can cause erosion of turbine blades. Oxide spallation is a serious problem for austenitic steels where the significant differences of the thermal expansion coefficients of steel and oxide cause relatively high thermal stresses. Usually, various oxides layered within the scale are suggested from microscopical observations of the morphology and/or topography of the oxide scale accompanied by the analysis of chemical elements present. Reports about the application of X-ray diffraction on the study of steamside oxide formation are very scarce in literature. If applied at all, XRD-studies are restricted to ideally flat samples oxidized under laboratory conditions, but relation to real operating conditions and the effect of the real sample geometry is missing. Within the frame of the project, steamside oxides on plant exposed components of ferritic/ martensitic X20CrMoV12-1 as well as fine- and coarse-grained austenitic TP347H were studied by means of X-ray diffraction. Depth dependent phase analysis on sample segments cut from the tubes was carried out by means of grazing incidence diffraction and, in order to obtain information from a larger depth, conventional XRD was combination with stepwise mechanical removal of the steamside oxides. After each removal step phase analysis was performed both on the segments and on the removed powders. Phase specific stress analysis was carried out on rings cut from the tube. Results show that steamside oxides on X20CrMoV12-1 consist of pure Hematite at the surface followed by a relatively thick layer of pure Magnetite. Both phases are under relatively high tensile stresses. While the phase composition of the Hematite layer appears to be the same for all
Section 608 Technician Certification Test Topics

Science.gov (United States)

Identifies some of the topics covered on Section 608 Technician Certification tests such as ozone depletion, the Clean Air Act and Montreal Protocol, Substitute Refrigerants and oils, Refrigeration and Recovery Techniques.
46 CFR 61.05-20 - Boiler safety valves.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Boiler safety valves. 61.05-20 Section 61.05-20 Shipping... INSPECTIONS Tests and Inspections of Boilers § 61.05-20 Boiler safety valves. Each safety valve for a drum, superheater, or reheater of a boiler shall be tested at the interval specified by table 61.05-10. [CGD 95-028...
Experimental result of BWR post-CHF tests. Critical heat flux and post-CHF heat transfer coefficient. Contract research

International Nuclear Information System (INIS)

Iguchi, Tadashi; Anoda, Yoshinari

2002-02-01

Authors performed post-CHF experiments under wider pressure ranges of 2 MPa - 18 MPa, wider mass flux ranges of 33 kg/m 2 s - 1651 kg/m 2 s and wider superheat of heaters up to 500 K in comparison to experimental ranges at previous post-CHF experiments. Data on boiling transition, critical heat flux and post-CHF heat transfer coefficient were obtained. Used test section was 4x4-rod bundle with heaters, which diameter and length were the same as those of BWR nuclear fuels. As the result of the experiments, it was found that the boiling transition occurred just below several grid spacers, and that the fronts of the boiling transition region proceeded lower with increase of heated power. Heat transfer was due to nucleate boiling above grid spacers, while it was due to film boiling below grid spacers. Consequently, critical heat flux is affected on the distance from the grid spacers. Critical heat flux above the grid spacers was about 15% higher than that below the grid spacers, by comparing them under the same local condition. Heat transfer by steam turbulent flow was dominant to post-CHF heat transfer, when superheat of heaters was sufficiently high. Then, post-CHF heat transfer coefficient was predicted with heat transfer correlations for single-phase flow. On the other hand, when superhead of heaters was not sufficiently high, post-CHF heat transfer coefficient was higher than the prediction with heat transfer correlations for single-phase flow. Mass flux effect on post-CHF heat transfer coefficient was described by standardization of post-CHF heat transfer coefficient with the prediction for single-phase flow. However, pressure effect, superheat effect and effect of position were not described. Authors clarified that those effects could be described with functions of heater temperature and position. Post-CHF heat transfer coefficient was lowest just blow the grid spacers, and it increased with the lower positions. It increased by about 30% in one span of the grid
Experimental result of BWR post-CHF tests. Critical heat flux and post-CHF heat transfer coefficient. Contract research

Energy Technology Data Exchange (ETDEWEB)

Iguchi, Tadashi; Anoda, Yoshinari [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Iwaki, Chikako [Toshiba Corp., Tokyo (Japan)

2002-02-01

Authors performed post-CHF experiments under wider pressure ranges of 2 MPa - 18 MPa, wider mass flux ranges of 33 kg/m{sup 2}s - 1651 kg/m{sup 2}s and wider superheat of heaters up to 500 K in comparison to experimental ranges at previous post-CHF experiments. Data on boiling transition, critical heat flux and post-CHF heat transfer coefficient were obtained. Used test section was 4x4-rod bundle with heaters, which diameter and length were the same as those of BWR nuclear fuels. As the result of the experiments, it was found that the boiling transition occurred just below several grid spacers, and that the fronts of the boiling transition region proceeded lower with increase of heated power. Heat transfer was due to nucleate boiling above grid spacers, while it was due to film boiling below grid spacers. Consequently, critical heat flux is affected on the distance from the grid spacers. Critical heat flux above the grid spacers was about 15% higher than that below the grid spacers, by comparing them under the same local condition. Heat transfer by steam turbulent flow was dominant to post-CHF heat transfer, when superheat of heaters was sufficiently high. Then, post-CHF heat transfer coefficient was predicted with heat transfer correlations for single-phase flow. On the other hand, when superhead of heaters was not sufficiently high, post-CHF heat transfer coefficient was higher than the prediction with heat transfer correlations for single-phase flow. Mass flux effect on post-CHF heat transfer coefficient was described by standardization of post-CHF heat transfer coefficient with the prediction for single-phase flow. However, pressure effect, superheat effect and effect of position were not described. Authors clarified that those effects could be described with functions of heater temperature and position. Post-CHF heat transfer coefficient was lowest just blow the grid spacers, and it increased with the lower positions. It increased by about 30% in one span of
46 CFR 61.05-10 - Boilers in service.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Boilers in service. 61.05-10 Section 61.05-10 Shipping... INSPECTIONS Tests and Inspections of Boilers § 61.05-10 Boilers in service. (a) Each boiler, including superheater, reheater, economizer, auxiliary boiler, low-pressure heating boiler, and unfired steam boiler...
Complot test section outlet CFD optimization (pre - test and dimensioning)

International Nuclear Information System (INIS)

Profir, M. M.; Moreau, V.; Kennedy, G.

2013-01-01

In the framework of the FP7 MAXSIMA European project, the COMPLOT (COMPonent LOop Testing) LBE experimental facility is employed for thermal-hydraulic experiments aimed to test and qualify, among other components, a buoyancy driven safety/control rods (SR/CR) system, as key components for the safe operation of the MYRRHA reactor. This paper focuses mainly on a simplified CFD representation of the SR test section outlet in order to optimise it for the testing program. Parametric cases, associated with different positions of the SR assembly have been set up and analysed. A quasi-static analysis has been performed for each case, accounting for the LBE volume displaced by the insertion of the SR bundle, by introducing appropriately positioned additional mass sources. Velocity and pressure fields, as well as pressure drop magnitudes and mass flow rates through relevant guide tube hole outlets have been calculated and compared. The CFD analysis proved that the outer boundary of the test section does not impact the expected performance of the SR (rapid transient downward insertion). Preliminary simulations reproducing the timely repositioning of the SR/CR in COMPLOT using procedures of automatic volume mesh regeneration, consistently with the rod imposed displacement, are illustrated. (authors)
An experimental observation of the effect of flow direction for evaporation heat transfer in plate heat exchanger

International Nuclear Information System (INIS)

Lin, Yueh-Hung; Li, Guang-Cheng; Yang, Chien-Yuh

2015-01-01

This study provides an Infrared Thermal Image observation on the evaporation heat transfer of refrigerant R-410A in plate heat exchanger with various flow arrangement and exit superheat conditions. An experimental method was derived for estimating the superheat region area of two-phase refrigerant evaporation in plate heat exchanger. The experimental results show that the superheat region area for parallel flow is much larger than that for counter flow as that estimated by Yang et al. [9]. There is an early superheated region at the central part of the plate heat exchanger for parallel flow arrangement. This effect is not significant for counter flow arrangement. The Yang et al. [9] method under estimated the superheat area approximately 40%–53% at various flow rates and degree of exit superheat. Even though the flow inside a plate heat exchanger is extremely turbulent because of the chevron flow passages, the assumption of uniform temperature distribution in the cross section normal to the bulk flow direction will cause significant uncertainties for estimating the superheat area for refrigerant evaporating in a plate heat exchanger
High temperature corrosion in straw-fired power plants: Influence of steam/metal temperature on corrosion rates for TP347H

DEFF Research Database (Denmark)

Montgomery, Melanie; Biede, O; Larsen, OH

2002-01-01

The corrosion in straw-fired boilers has been investigated at various straw-fired power plants in Denmark. Water/air-cooled probes, a test superheater and test sections removed from the actual superheater have been utilised to characterise corrosion and corrosion rates. This paper describes...... the corrosion rates measured for the TP347H type steel. The corrosion morphology at high temperature consists of grain boundary attack and selective attack of chromium. The corrosion rate increases with calculated metal temperature (based on steam temperature), however there is great variation within....... The difference in the results could be traced back to a lower flue gas temperature on one side of the boiler. Although metal temperature is the most important parameter with respect to corrosion rate, flue gas temperature also plays an important role. Efforts to quantify the effect of flue gas temperature...
A "Projective" Test of the Golden Section Hypothesis.

Science.gov (United States)

Lee, Chris; Adams-Webber, Jack

1987-01-01

In a projective test of the golden section hypothesis, 24 high school students rated themselves and 10 comic strip characters on basis of 12 bipolar constructs. Overall proportion of cartoon figures which subjects assigned to positive poles of constructs was very close to golden section. (Author/NB)
Pressure tests to assess the significance of defects in boiler and superheater tubing

International Nuclear Information System (INIS)

Guest, J.C.; Hutchings, J.A.

1975-01-01

Internal pressure tests on 9 per cent Cr-1 per cent Mo steel tubing containing artificial defects demonstrated that the resultant loss of strength was less than a simple calculation based on the reduced tube thickness would suggest. Bursting tests on tubes containing longitudinal defects of varying length, depth and acuity showed notch strengthening at ambient temperature and at 550 0 C. A flow stress concept developed for simple bursting tests was shown to apply to creep conditions at 550 0 C. Results of creep and short-term bursting tests show that the length as well as the depth of the defect is an important factor affecting the life of bursting strength of the tubes. Defects less than 10 per cent of the tube thickness were found to have an insignificant effect. (author)
CFRMF spectrum update and application to dosimeter cross-section data testing

International Nuclear Information System (INIS)

Anderl, R.A.; Harker, Y.D.; Millsap, D.A.; Rogers, J.W.; Ryskamp, J.M.

1982-01-01

The Coupled Fast Reactivity Measurements Facility (CFRMF) at the Idaho National Engineering Laboratory (INEL) is a Cross Section Evaluation Working Group (CSEWG) benchmark for data testing of dosimetry, fission-product and actinide cross sections important to fast-reactor technology. In this paper we present the results of our work in updating the CFRMF spectrum characterization and in applying CFRMF integral data to testing ENDF/B-V dosimeter cross sections. Updated characterization of the central neutron spectrum includes the results of neutronics calculations with ENDF/B-V nuclear data, the generation of a fine-group spectrum representation for integral data-testing applications, and a sensitivity and uncertainty analysis which provides a flux-spectrum covariance matrix related to uncertainties and correlations in the nuclear data used in a neutronics calculation. Our application of CFRMF integral data to cross section testing has included both conventional integral testing analyses and least-squares-adjustment analyses with the FERRET code. The conventional integral data-testing analysis, based on C/E ratios, indicates discrepancies outside the estimated integral test uncertainty for the 6 Li(n,He), 10 B(n,He), 47 Ti(n,p), 58 Fe(n,γ), 197 Au(n,γ) and 232 Th(n,γ) cross sections. The integral test uncertainty included contributions from the measured integral data and from the spectrum and cross sections used to obtain the calculated integral data. Within the uncertainty and correlation specifications for the input spectrum and dosimeter cross sections, the least-squares-adjustment analysis indicated a high degree of consistency between the measured integral data and the ENDF/B-V dosimeter cross sections for all reactions except 10 B
The experimental and engineering programmes to support the PFR Safety Case following the Superheater 2 under sodium leak: In particular, large scale experiments in the Super Noah Rig at Dounreay

International Nuclear Information System (INIS)

Currie, R.; Henderson, J.D.C.

1990-01-01

The original safety Case for the Prototype Fast Reactor (PFR) at Dounreay was based on the Double-ended-guillotine failure (DEGF) of one tube followed by six more DEGFs spread out at 3s intervals. Because the DEGF flowrate in the Evaporator units was considerably greater than those for the Superheater and Reheater units, pressure loading predictions were based on a leak incident in the Evaporator. As data became available from sodium-water reaction experiments, this Design Basis Accident (DBA) was revised to be the failure of a single tube (1DEGF). Pressure loadings for the plant were still based on the Evaporator. The plant was, however, designed against the original DBA of 1+6 DEGFs. The under sodium leak in Superheater 2, in which a total of 40 DEGFs occurred in a short period of time, cast doubt on the choice of DBA for PFR and it was obvious that multiple tube failure incidents had to be considered. A revised Safety Case for PFR was constructed based on an event tree and is presented in this paper. Also, in this paper the engineering work carried out on the plant in order to reduce the frequency of occurrence of multiple tube failures and the R and D programme initiated to remove unnecessary pessimism from the postulated multiple tube failure incidents are described. (author). 2 refs, 16 figs, 1 tab
Modification of heating system on HeaTiNG-02 test section of beta test loop

International Nuclear Information System (INIS)

Sagino; Dedy Haryanto; Riswan Djambiar; Edy Sumarno

2013-01-01

Modifications have been carried out on the heating test section heating-02 on the integration strand Beta Test (UUB). The activities carried out to overcome the obstacles that arise in the test section when used. Constraint that often arises is the fall of the heating source super chantal when it reaches a certain temperature. To mitigate the super chantal is initially converted into a horizontal vertical position. Change from vertical to horizontal position on super chantal aims to stabilize the position of super chantal, so it needs to be modified in the heating system. Modification activities include manufacturing, installation and testing of super chantal and refractory stone as super chantal support. Manufacturing refractory stone formation and assembly into the heater in accordance with design modifications that have been done in electromechanical workshop obtained using some machine tools. Testing results of fabrication has been done by providing voltage 110 volts until it reaches operating temperature 400°C. Test results obtained super chantal stable position when it reaches operating temperature, and heater of heating-02 test section feasible to be used for experiments. (author)
Rapid evaporation at the superheat limit of methanol, ethanol, butanol and n-heptane on platinum films supported by low-stress SiN membranes.

Science.gov (United States)

Ching, Eric J; Avedisian, C Thomas; Cavicchi, Richard C; Chung, Do Hyun; Rah, Jeff; Carrier, Michael J

2016-10-01

The bubble nucleation temperatures of several organic liquids (methanol, ethanol, butanol, n-heptane) on stress-minimized platinum (Pt) films supported by SiN membranes is examined by pulse-heating the membranes for times ranging from 1 µs to 10 µs. The results show that the nucleation temperatures increase as the heating rates of the Pt films increase. Measured nucleation temperatures approach predicted superheat limits for the smallest pulse times which correspond to heating rates over 10 8 K/s, while nucleation temperatures are significantly lower for the longest pulse times. The microheater membranes were found to be robust for millions of pulse cycles, which suggests their potential in applications for moving fluids on the microscale and for more fundamental studies of phase transitions of metastable liquids.
Separators/reheaters for nuclear turbines

International Nuclear Information System (INIS)

Guignard, S.

1986-01-01

During the past few years, the Nuclear Department of Stein Industrie has implemented a broad development programme for the design of superheating separators for nuclear power plant turbines. These units separate the water in the steam leaving the high-pressure section, and superheat the dry steam before expansion in the medium - and low - pressure sections. Thorough research, confirmed by tests, was conducted in different areas, and especially on problems of water and steam separation, and heat transfers in the tube bundle(s) required to superheat the steam. Special systems were designed to avoid processes detrimental to the operation of the units, such as vibrations, erosion/corrosion etc. Experimental feedback on the superheating separators of 900 MW nuclear power plants helped to substantiate the assumptions made for the thermal and hydraulic calculations, as well as the optimizations carried out on the different functions. These results confirmed the industrial application of the design methods to other superheating separators intended for 1300 MW nuclear power plants and for export [fr
Heat transfer characteristics evaluation of heat exchangers of mock-up test facility with full-scale reaction tube for HTTR hydrogen production system (Contract research)

International Nuclear Information System (INIS)

Shimizu, Akira; Ohashi, Hirofumi; Kato, Michio; Hayashi, Koji; Aita, Hideki; Nishihara, Tetsuo; Inaba, Yoshitomo; Takada, Shoji; Morisaki, Norihiro; Sakaki, Akihiro; Maeda, Yukimasa; Sato, Hiroyuki; Inagaki, Yoshiyuki; Hanawa, Hiromi; Fujisaki, Katsuo; Yonekawa, Hideo

2005-06-01

Connection of hydrogen production system by steam reforming of methane to the High Temperature Engineering Test Reactor (HTTR) of the Japan Atomic Energy Research Institute (JAERI) has been surveyed until now. Mock-up test facility of this steam reforming system with full-scale reaction tube was constructed in FY 2001 and hydrogen of 120 Nm 3 /h was successfully produced in overall performance test. Totally 7 times operational tests were performed from March 2002 to December 2004. A lot of operational test data on heat exchanges were obtained in these tests. In this report specifications and structures of steam reformer, steam superheater, steam generator, condenser, helium gas cooler, feed gas heater and feed gas superheater were described. Heat transfer correlation equations for inside and outside tube were chosen from references. Spreadsheet programs were newly made to evaluate heat transfer characteristics from measured test data such as inlet and outlet temperature pressure and flow-rate. Overall heat-transfer coefficients obtained from the experimental data were compared and evaluated with the calculated values with heat transfer correlation equation. As a result, actual measurement values of all heat exchangers gave close agreement with the calculated values with correlation equations. Thermal efficiencies of the heat exchangers were adequate as they were well accorded with design value. (author)
United States Advanced Ultra-Supercritical Component Test Facility for 760°C Steam Power Plants ComTest Project

Energy Technology Data Exchange (ETDEWEB)

Hack, Horst [Electric Power Research Institute (EPRI); Purgert, Robert Michael [Energy Industries of Ohio

2017-12-13

Following the successful completion of a 15-year effort to develop and test materials that would allow coal-fired power plants to be operated at advanced ultra-supercritical (A-USC) steam conditions, a United States-based consortium is presently engaged in a project to build an A-USC component test facility (ComTest). A-USC steam cycles have the potential to improve cycle efficiency, reduce fuel costs, and reduce greenhouse gas emissions. Current development and demonstration efforts are focused on enabling the construction of A-USC plants, operating with steam temperatures as high as 1400°F (760°C) and steam pressures up to 5000 psi (35 MPa), which can potentially increase cycle efficiencies to 47% HHV (higher heating value), or approximately 50% LHV (lower heating value), and reduce CO₂ emissions by roughly 25%, compared to today’s U.S. fleet. A-USC technology provides a lower-cost method to reduce CO₂ emissions, compared to CO₂ capture technologies, while retaining a viable coal option for owners of coal generation assets. Among the goals of the ComTest facility are to validate that components made from advanced nickel-based alloys can operate and perform under A-USC conditions, to accelerate the development of a U.S.-based supply chain for the full complement of A-USC components, and to decrease the uncertainty of cost estimates for future A-USC power plants. The configuration of the ComTest facility would include the key A-USC technology components that were identified for expanded operational testing, including a gas-fired superheater, high-temperature steam piping, steam turbine valve, and cycling header component. Membrane walls in the superheater have been designed to operate at the full temperatures expected in a commercial A-USC boiler, but at a lower (intermediate) operating pressure. This superheater has been designed to increase the temperature of the steam supplied by the host utility boiler up to 1400°F (760�
A test section design to simulate horizontal two-phase air-water flow

International Nuclear Information System (INIS)

Faccini, Jose Luiz H.; Cesar, Silvia B.G.; Coutinho, Jorge A.; Freitas, Sergio Carlos; Addor, Pedro N.

2002-01-01

In this work an air-water two-phase flow horizontal test section assembling at Nuclear Engineering Institute (IEN) is presented. The test section was designed to allow four-phase flow patterns to be simulated: bubble flow, stratified flow, wave flow and slug flow. These flow patterns will be identified by non-conventional ultrasonic techniques which have been developed to meet this particular application. Based on the separated flow and drift-flux models the test section design steps are shown. A description of the test section and its instrumentation and data acquisition system is also provided. (author)

Experimental Investigation of Heat Pipe Startup Under Reflux Mode

Science.gov (United States)

Ku, Jentung

2018-01-01

In the absence of body forces such as gravity, a heat pipe will start as soon as its evaporator temperature reaches the saturation temperature. If the heat pipe operates under a reflux mode in ground testing, the liquid puddle will fill the entire cross sectional area of the evaporator. Under this condition, the heat pipe may not start when the evaporator temperature reaches the saturation temperature. Instead, a superheat is required in order for the liquid to vaporize through nucleate boiling. The amount of superheat depends on several factors such as the roughness of the heat pipe internal surface and the gravity head. This paper describes an experimental investigation of the effect of gravity pressure head on the startup of a heat pipe under reflux mode. In this study, a heat pipe with internal axial grooves was placed in a vertical position with different tilt angles relative to the horizontal plane. Heat was applied to the evaporator at the bottom and cooling was provided to the condenser at the top. The liquid-flooded evaporator was divided into seven segments along the axial direction, and an electrical heater was attached to each evaporator segment. Heat was applied to individual heaters in various combinations and sequences. Other test variables included the condenser sink temperature and tilt angle. Test results show that as long as an individual evaporator segment was flooded with liquid initially, a superheat was required to vaporize the liquid in that segment. The amount of superheat required for liquid vaporization was a function of gravity pressure head imposed on that evaporator segment and the initial temperature of the heat pipe. The most efficient and effective way to start the heat pipe was to apply a heat load with a high heat flux to the lowest segment of the evaporator.
Environmental Assessment for Authorizing the Puerto Rico Electric Power Authority (PREPA) to allow Public Access to the Boiling Nuclear Superheat (BONUS) Reactor Building, Rincon, Puerto Rico

International Nuclear Information System (INIS)

2003-01-01

The U.S. Department of Energy (DOE) proposes to consent to a proposal by the Puerto Rico Electric Power Authority (PREPA) to allow public access to the Boiling Nuclear Superheat (BONUS) reactor building located near Rincon, Puerto Rico for use as a museum. PREPA, the owner of the BONUS facility, has determined that the historical significance of this facility, as one of only two reactors of this design ever constructed in the world, warrants preservation in a museum, and that this museum would provide economic benefits to the local community through increased tourism. Therefore, PREPA is proposing development of the BONUS facility as a museum
Pilot instrumentation of a Superpave test section at the Kansas Accelerated Testing laboratory

Science.gov (United States)

2003-04-01

Two Superpave test sections were constructed at the Kansas Accelerated Testing Laboratory (K-ATL) with 12.5 mm (2 in) nominal maximum size Superpave mixture (SM-2A) with varying percentages (15 and 30 percent) of river sand. A 150 kN (34 kip) tandem ...
Comparison between two rheocasting processes of damper cooling tube method and low superheat casting

Directory of Open Access Journals (Sweden)

Zhang Xiaoli

2014-09-01

Full Text Available To produce a high quality semisolid slurry that consists of fine primary particles uniformly suspended in the liquid matrix for rheoforming, chemical refining and electromagnetic or mechanical stirring are the two methods commonly used. But these two methods either contaminate the melt or incur high cost. In this study, the damper cooling tube (DCT method was designed to prepare semisolid slurry of A356 aluminum alloy, and was compared with the low superheat casting (LSC method - a conventional process used to produce casting slab with equiaxed dendrite microstructure for thixoforming route. A series of comparative experiments were performed at the pouring temperatures of 650 °C, 638 °C and 622 °C. Metallographic observations of the casting samples were carried out using an optical electron microscope with image analysis software. Results show that the microstructure of semisolid slurry produced by the DCT process consists of spherical primary α-Al grains, while equiaxed grains microstructure is found in the LSC process. The lower the pouring temperature, the smaller the grain size and the rounder the grain morphology in both methods. The copious nucleation, which could be generated in the DCT, owing to the cooling and stirring effect, is the key to producing high quality semisolid slurry. DCT method could produce rounder and smaller α-Al grains, which are suitable for semisolid processing; and the equivalent grain size is no more than 60 μm when the pouring temperature is 622 °C.
Sealing performance test for main flange of pressure vessel of T2 test section in HENDEL

International Nuclear Information System (INIS)

Ioka, Ikuo; Inagaki, Yoshiyuki; Matsumoto, Kiminori; Kondou, Yasuo; Suzuki, Kunihiko; Miyamoto, Yoshiaki; Asami, Masanobu.

1990-12-01

A pressure vessel of T 2 test section in helium engineering demonstration loop (HENDEL) was fabricated to the same scale of the reactor pressure vessel made of 2(1/4)Cr-1Mo steel in high temperature engineering test reactor (HTTR). Also, the sealing structure of a main flange of pressure vessel in T 2 test section was composed of the double metal O-rings and Ω-seal which would be used in the sealing structure of HTTR. The sealing performance test for the main flange of the pressure vessel in T 2 test section was carried out to confirm the integrity of sealing structure of a main flange in HTTR. T 2 test section has been operated about 7700 hours in previous 18 cycles. The leakage of helium gas from inner metal O-ring was measured by the static pressurized process under the operating condition of HTTR (helium gas: 400degC, 40kg/cm 2 G, 4gk/s). The calculated leakage of helium gas was less than 9.6x10 -7 atm·cm 3 /sec. From the result, it is expected that the sealing structure of main flange in HTTR would maintain the leak tightness in the life. (author)
Thermodynamic and heat transfer analysis of heat recovery from engine test cell by Organic Rankine Cycle

Science.gov (United States)

Shokati, Naser; Mohammadkhani, Farzad; Farrokhi, Navid; Ranjbar, Faramarz

2014-12-01

During manufacture of engines, evaluation of engine performance is essential. This is accomplished in test cells. During the test, a significant portion of heat energy released by the fuel is wasted. In this study, in order to recover these heat losses, Organic Rankine Cycle (ORC) is recommended. The study has been conducted assuming the diesel oil to be composed of a single hydrocarbon such as C12H26. The composition of exhaust gases (products of combustion) have been computed (and not determined experimentally) from the stoichiometric equation representing the combustion reaction. The test cell heat losses are recovered in three separate heat exchangers (preheater, evaporator and superheater). These heat exchangers are separately designed, and the whole system is analyzed from energy and exergy viewpoints. Finally, a parametric study is performed to investigate the effect of different variables on the system performance characteristics such as the ORC net power, heat exchangers effectiveness, the first law efficiency, exergy destruction and heat transfer surfaces. The results of the study show that by utilizing ORC, heat recovery equivalent to 8.85 % of the engine power is possible. The evaporator has the highest exergy destruction rate, while the pump has the lowest among the system components. Heat transfer surfaces are calculated to be 173.6, 58.7, and 11.87 m2 for the preheater, evaporator and superheater, respectively.
Testing Cross-Sectional Correlation in Large Panel Data Models with Serial Correlation

Directory of Open Access Journals (Sweden)

Badi H. Baltagi

2016-11-01

Full Text Available This paper considers the problem of testing cross-sectional correlation in large panel data models with serially-correlated errors. It finds that existing tests for cross-sectional correlation encounter size distortions with serial correlation in the errors. To control the size, this paper proposes a modification of Pesaran’s Cross-sectional Dependence (CD test to account for serial correlation of an unknown form in the error term. We derive the limiting distribution of this test as N , T → ∞ . The test is distribution free and allows for unknown forms of serial correlation in the errors. Monte Carlo simulations show that the test has good size and power for large panels when serial correlation in the errors is present.
Final Report, Materials for Industrial Heat Recovery Systems, Tasks 3 and 4 Materials for Heat Recovery in Recovery Boilers

Energy Technology Data Exchange (ETDEWEB)

Keiser, James R.; Kish, Joseph R.; Singh, Preet M.; Sarma, Gorti B.; Yuan, Jerry; Gorog, J. Peter; Frederick, Laurie A.; Jette, Francois R.; Meisner, Roberta A.; Singbeil, Douglas L.

2007-12-31

tubes. Also, these fluctuating air flow patterns can result in deposition of black liquor on the wall tubes, and during periods when deposition is high, there is a noticeable increase in the concentrations of sulfur-bearing gases like hydrogen sulfide and methyl mercaptan. Laboratory studies have shown that chromized and aluminized surface treatments on carbon steel improve the resistance to sulfidation attack. Studies of superheater corrosion and cracking have included laboratory analyses of cracked tubes, laboratory corrosion studies designed to simulate the superheater environment and field tests to study the movement of superheater tubes and to expose a corrosion probe to assess the corrosion behavior of alternate superheater alloys, particularly alloys that would be used for superheaters operating at higher temperatures and higher pressures than most current boilers. In the laboratory corrosion studies, samples of six alternate materials were immersed in an aggressive, low melting point salt mixture and exposed for times up to 336 h, at temperatures of 510, 530 or 560°C in an inert or reactive cover gas. Using weight change and results of metallographic examination, the samples were graded on their resistance to the various environments. For the superheater corrosion probe studies, samples of the same six materials were exposed on an air-cooled corrosion probe exposed in the superheater section of a recovery boiler for 1000 h. Post exposure examination showed cracking and/or subsurface attack in the samples exposed at the higher temperatures with the attack being more severe for samples 13 exposed above the first melting temperature of the deposits that collected on the superheater tubes. From these superheater studies, a ranking was developed for the six materials tested. The task addressing cracking and corrosion of primary air port tubes that was part of this project produced results that have been extensively implemented in recovery boilers in North America
Properties of thick welded joints on superheater collectors made from new generation high alloy martensitic creep-resisting steels for supercritical parameters

Energy Technology Data Exchange (ETDEWEB)

Dobrzanski, Janusz; Zielinski, Adam [Institute for Ferrous Metallurgy, Gliwice (Poland); Pasternak, Jerzy [Boiler Engineering Company RAFAKO S.A., Raciborz (Poland)

2010-07-01

The continuously developing power generation sector, including boilers with supercritical parameters, requires applications of new creep-resistant steel grades for construction of boilers steam superheater components. This paper presents selected information, experience within the field of research and implementation of a new group of creep-resistant as X10CrMoVNb9-1(P91), X10CrWMoVNb9-2(P92) and X12CrCoWVNb12-2-2(VM12) grades, containing 9-12%Cr. During welding and examination process the results of mechanical properties, requested level for base material and welded joints, as well as: tensile strength, impact strength and technological properties have been evaluated. Additional destructive examinations, with evaluation of structure stability, hardness distribution, for base material and welded joints after welding, heat treatment, again process have been determined. Recommendations due to the implementation influence of operating parameters of the main boiler components are part of this paper. (orig.)
High temperature corrosion in biomass- and waste fired boilers. A status report; Kunskapslaeget betraeffande hoegtemperaturkorrosion i aangpannor foer biobraensle och avfall

Energy Technology Data Exchange (ETDEWEB)

Henderson, P; Ifwer, K; Staalenheim, A; Montgomery, M; Hoegberg, J; Hjoernhede, A

2006-12-15

Many biomass- or waste-fired plants have problems with high temperature corrosion on the furnace walls or at the superheaters, especially if the steam temperature is greater than 500 deg C. An increase in the combustion of waste fuels means that an increasing number of boilers have had problems. Therefore, there is great interest from plant owners to reduce the costs associated with high temperature corrosion. At the same time there exists a considerable driving force towards improving the electrical efficiency of a plant by the use of more advanced steam data. The purpose of the work presented here was to answer three main questions: What can be done to reduce high temperature corrosion with current fuel blends and steam temperatures? How can more waste fuels be burnt without an increased risk for corrosion? What needs to be done to reach higher steam temperatures in the future? The level of knowledge of high temperature corrosion in biomass- and waste-fired boilers has been described and summarised. The following measures are recommended to reduce corrosion in existing plant: Make sure that the fuel is well mixed and improve fuel feeding to obtain a more even spread of the fuel over the cross-section of the boiler. Use combustion technology methods to stabilize the oxygen content of the flue gases near the membrane walls and other heat transfer surfaces. Experiment with additives and/or supplementary fuels which contain sulphur in some form, for example peat. Reduce the flue gas temperature at the superheaters. Review soot-blowing procedures or protect heat transfer surfaces from soot blowers. Evaluate coated membrane wall panels in parts of the furnace that experience the worst corrosion. Test more highly alloyed steels suitable for superheaters and when replacing a superheater change to a more highly alloyed steel. For the future, the following should be considered: The role of sulphur needs to be investigated more and other additives should be investigated
Transient modeling of an air-cooled chiller with economized compressor. Part II: Application to control design

International Nuclear Information System (INIS)

Zhang Weijiang; Ding Shufu; Zhang Chunlu

2009-01-01

Based on the transient modeling developed in the previous paper, the control design of the air-cooled chiller is studied. The main electronic expansion valve (EXV) controls the suction superheat, the compressor controls the leaving water temperature and the sub EXV regulates the injection superheat. Since the system reliability is sensitive to the control of the suction superheat, it is the focus in this paper. Dynamic simulation cases are built to compare two control algorithms, PID and fuzzy logic. The case studies show that the fuzzy controller has higher reliability and performance. Both the two controllers are fully tested and tuned on a chiller test facility and the experiments indicate that the fuzzy controller works better as well.
Experimental study of nonequilibrium post-chf heat transfer in rod bundles

International Nuclear Information System (INIS)

Unal, C.; Tuzla, K.; Badr, O.; Neti, S.; Chen, J.

1986-01-01

Verifications and improvements of nonequilibrium heat transfer models, for post-critical-heat-flux convective boiling, has been greatly affected by the lack of experimental data regarding the degree of thermodynamic nonequilibrium. Recent studies had been successful in measuring vapor superheats in a vertical single tube. This paper extends the nonequilibrium convective boiling data to a rod bundle geometry. Vapor superheat measurements were obtained in a rod bundle with nine heated rods and a heated shroud. Tests were carried out with water at low mass fluxes with a wide range of dryout conditions. Significant nonequilibrium was observed, with vapor superheats of up to 600 0 C. Parametric effects of mass flux, heat flux and inlet conditions on vapor superheat are presented
Tool for assistance in testing the safety logic section of nuclear plants

International Nuclear Information System (INIS)

Boulc'h, J.; Meur, M. le; Collart, J.M.; Segalard, J.; Uberschlag, J.

1986-01-01

The analysis of the protection system logic section (SPIN) of the PALUEL plant performed manually have led to the study of a logical tool for testing the safety logic section having or having not failures. It is a dynamic analyser which from a terminal in a sharing time system will be able to generate testing sequences, to simulate a processor and its environment and to analyse the logic sections with their workable code
The design of in-pile test section for fuel test loop

Energy Technology Data Exchange (ETDEWEB)

Park, K. N.; Lee, J. M.; Shim, B. S.; Zee, D. Y.; Park, S. H.; Ahn, S. H.; Lee, J. Y.; Kim, Y. J. [KAERI, Taejon (Korea, Republic of)

2004-07-01

As an equipment for nuclear fuel's general performance irradiation test in HANARO, Fuel Test Loop(FTL) has been developed that can irradiate the pin to the maximum number of 3 at the core irradiation hole(IR1 hole) by considering for it's utility and user's irradiation requirement. 3-Pin FTL consists of In-Pile Test Section (IPS) and Out-of-Pile System (OPS). IPS consists for IPS Vessel assembly, In-Pool Piping, IPS Support, In-Pool Piping Support etc. Design that such IPS considers interference item consisted to do not bear in existing facilities by one. IVA that is connected to the OPS are controlled and regulated by means of system pressure, system temperature and the water quality. IPS Vessel assembly is consisted of outer pressure vessel, inner pressure vessel, IPS head, inner assembly and test fuel carrier. After 3-Pin FTL development which is expected to be finished by the 2006, FTL will be used for the irradiation test of the new PWR-type fuel and can maximize the usage of HANARO.
Augmented Cross-Sectional Prevalence Testing for Estimating HIV Incidence

OpenAIRE

Wang, R.; Lagakos, S. W.

2010-01-01

Estimation of an HIV incidence rate based on a cross-sectional sample of individuals evaluated with both a sensitive and less-sensitive diagnostic test offers important advantages to incidence estimation based on a longitudinal cohort study. However, the reliability of the cross-sectional approach has been called into question because of two major concerns. One is the difficulty in obtaining a reliable external approximation for the mean “window period” between detectability of HIV infection ...
Field test corrosion experiences when co-firing straw and coal: 10 year status within Elsam

DEFF Research Database (Denmark)

Frandsen, Rasmus Berg; Montgomery, Melanie; Larsen, Ole Hede

2007-01-01

and straw at the 150 MW pulverized coal fired boiler Studstrup unit 1. Two exposure series lasting 3000 hours each were performed for co-firing 10 and 20% of straw (% energy basis) with coal. Using built in test tubes in the hot end of the actual superheaters and air/water cooled corrosion probes...... to 575 degrees C and for the flue gas from 1025 to 1300 degrees C. All these test tubes have been removed during the last three years at one year intervals for corrosion studies. The corrosion studies performed on all investigated tubes included measurements of the corrosion attack, light optical...
Experimental test results of multi-channel test rig of T1 test section, 5

International Nuclear Information System (INIS)

Hino, Ryutaro; Takase, Kazuyuki; Miyamoto, Yoshiaki

1990-09-01

Channel blockage test on a fuel column of the high temperature engineering test reactor (HTTR) has been performed under the helium gas atmosphere at a high temperature and a high pressure in order to obtain safety data on flow rate and temperature distributions in the fuel column with the multi-channel test rig of the fuel stack test section (T 1 ) in HENDEL. In the test, one of 12 fuel channels was blockaded to 90% of flow area at the channel inlet. Experimental results showed that the helium gas flow rate in the blockaded channel was 28%∼33% lower than the average flow rate for Reynolds number from 2300 to 14000 in isothermal flow. When simulated fuel rods were heated, the flow rate in the blockaded channel did not decrease down in comparison with the isothermal flow. This is due to that the heat generated in the fuel rods conducts to the other fuel channels in graphite fuel blocks, so that accelerated pressure losses in the fuel channels change with helium gas temperatures. (author)
Suppression of background noise in a transonic wind-tunnel test section

Science.gov (United States)

Schutzenhofer, L. A.; Howard, P. W.

1975-01-01

Some exploratory tests were recently performed in the transonic test section of the NASA Marshall Space Flight Center 14-in. wind tunnel to suppress the background noise. In these tests, the perforated walls of the test section were covered with fine wire screens. The screens eliminated the edge tones generated by the holes in the perforated walls and significantly reduced the tunnel background noise. The tunnel noise levels were reduced to such a degree by this simple modification at Mach numbers 0.75, 0.9, 1.1, 1.2, and 1.46 that the fluctuating pressure levels of a turbulent boundary layer could be measured on a 5-deg half-angle cone.
Test of RIPL-2 cross section calculations

International Nuclear Information System (INIS)

Herman, M.

2002-01-01

The new levels and optical segments and microscopic HF-BCS level densities (part of the density segment) were tested in practical calculations of cross sections for neutron induced reactions on 22 targets (40-Ca, 47-Ti, 52-Cr, 55-Mn, 58-Ni, 63-Cu, 71-Ga, 80-Se, 92-Mo, 93-Nb, 100-Mo, 109-Ag, 114-Cd, 124-Sn, 127-I, 133-Cs, 140-Ce, 153-Eu, 169-Tm, 186-W, 197-Au, 208-Pb). For each target all reactions involving up to 3 neutron, 1 proton and 1 α-particle emissions (subject to actual reaction thresholds) were considered in the incident energy range from 1 keV up to 20 MeV (in some cases up to 27 MeV). In addition, total, elastic, and neutron capture cross sections were calculated
Vertical drop test of a transport fuselage center section including the wheel wells

Science.gov (United States)

Williams, M. S.; Hayduk, R. J.

1983-01-01

A Boeing 707 fuselage section was drop tested to measure structural, seat, and anthropomorphic dummy response to vertical crash loads. The specimen had nominally zero pitch, roll and yaw at impact with a sink speed of 20 ft/sec. Results from this drop test and other drop tests of different transport sections will be used to prepare for a full-scale crash test of a B-720.

Finite Element Simulations of Two Vertical Drop Tests of F-28 Fuselage Sections

Science.gov (United States)

Jackson, Karen E.; Littell, Justin D.; Annett, Martin S.; Haskin, Ian M.

2018-01-01

In March 2017, a vertical drop test of a forward fuselage section of a Fokker F-28 MK4000 aircraft was conducted as part of a joint NASA/FAA project to investigate the performance of transport aircraft under realistic crash conditions. In June 2017, a vertical drop test was conducted of a wing-box fuselage section of the same aircraft. Both sections were configured with two rows of aircraft seats, in a triple-double configuration. A total of ten Anthropomorphic Test Devices (ATDs) were secured in seats using standard lap belt restraints. The forward fuselage section was also configured with luggage in the cargo hold. Both sections were outfitted with two hat racks, each with added ballast mass. The drop tests were performed at the Landing and Impact Research facility located at NASA Langley Research Center in Hampton, Virginia. The measured impact velocity for the forward fuselage section was 346.8-in/s onto soil. The wing-box section was dropped with a downward facing pitch angle onto a sloping soil surface in order to create an induced forward acceleration in the airframe. The vertical impact velocity of the wing-box section was 349.2-in/s. A second objective of this project was to assess the capabilities of finite element simulations to predict the test responses. Finite element models of both fuselage sections were developed for execution in LS-DYNA(Registered Trademark), a commercial explicit nonlinear transient dynamic code. The models contained accurate representations of the airframe structure, the hat racks and hat rack masses, the floor and seat tracks, the luggage in the cargo hold for the forward section, and the detailed under-floor structure in the wing-box section. Initially, concentrated masses were used to represent the inertial properties of the seats, restraints, and ATD occupants. However, later simulations were performed that included finite element representations of the seats, restraints, and ATD occupants. These models were developed to more
Modeling and Simulation of a Nuclear Fuel Element Test Section

Science.gov (United States)

Moran, Robert P.; Emrich, William

2011-01-01

"The Nuclear Thermal Rocket Element Environmental Simulator" test section closely simulates the internal operating conditions of a thermal nuclear rocket. The purpose of testing is to determine the ideal fuel rod characteristics for optimum thermal heat transfer to their hydrogen cooling/working fluid while still maintaining fuel rod structural integrity. Working fluid exhaust temperatures of up to 5,000 degrees Fahrenheit can be encountered. The exhaust gas is rendered inert and massively reduced in temperature for analysis using a combination of water cooling channels and cool N2 gas injectors in the H2-N2 mixer portion of the test section. An extensive thermal fluid analysis was performed in support of the engineering design of the H2-N2 mixer in order to determine the maximum "mass flow rate"-"operating temperature" curve of the fuel elements hydrogen exhaust gas based on the test facilities available cooling N2 mass flow rate as the limiting factor.
Development of heat transfer models for gap cooling

Energy Technology Data Exchange (ETDEWEB)

Kohriyama, Tamio; Murase, Michio; Tamaki, Tomohiko [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

2001-09-01

In a severe accident of a light water reactor (LWR), heat transfer models in a narrow annular gap between superheated core debris and a reactor pressure vessel (RPV) are important to evaluate the integrity of RPV and emergency procedures. This paper discusses the effects of superheat on the heat flux based on existing data. In low superheat conditions, the heat flux in the narrow gap is higher than the heat flux in pool nucleate boiling due to restricted flow area. It approaches the nucleate boiling heat flux as superheat increasing and reaches a critical value subject to the counter-current flow limiting (CCFL) at the top end of the gap. A heat transfer correlation was derived as a function of dimensionless superheat and a Kutateladze-type CCFL correlation was deduced for critical heat flux (CHF) restricted by CCFL, which gave good prediction for a wide range of the CHF data. Effect of an angle of inclination of the gap could also be incorporated in the CCFL correlation. In high superheat conditions, the heat flux in the narrow gap maintains a similar shape to the pool boiling curve but shifts the position to a higher superheated side than the pool boiling except film boiling, which could be expressed by the typical pool film boiling correlation. Incorporating quench test data, the heat flux correlation was derived as a function of dimensionless superheat using the same formula for the low superheat and the Kutateladze-type CCFL correlation was deduced for CHF. The CHF at the high superheat was 3-4 times as large as CHF at the low superheat and this difference was well predicted by different flow patterns in the gap and the balance of pressure gradients between gas and liquid phases. (author)
Investigations on the propagation of free surface boiling in a vertical superheated liquid column

International Nuclear Information System (INIS)

Das, P.K.; Bhat, G.S.; Arakeri, V.H.

1987-01-01

Some experimental studies on boiling propagation in a suddenly depressurized superheated vertical liquid column are reported. The propagation velocity of this phase change has been measured using an optical method. This velocity is strongly dependent on liquid superheat, liquid purity and test section size. The measured velocities of less than 5 m s -1 are significantly lower than the sonic velocity. Present observations suggest that the dominant mechanism for boiling propagation is convection. (author)
Investigations on the propagation of free surface boiling in a vertical superheated liquid column

Energy Technology Data Exchange (ETDEWEB)

Das, P.K.; Bhat, G.S.; Arakeri, V.H.

1987-04-01

Some experimental studies on boiling propagation in a suddenly depressurized superheated vertical liquid column are reported. The propagation velocity of this phase change has been measured using an optical method. This velocity is strongly dependent on liquid superheat, liquid purity and test section size. The measured velocities of less than 5 m s/sup -1/ are significantly lower than the sonic velocity. Present observations suggest that the dominant mechanism for boiling propagation is convection.
The fabrication of a vanadium-stainless steel test section for MHD testing of insulator coatings in flowing lithium

International Nuclear Information System (INIS)

Reed, C.B.; Mattas, R.F.; Smith, D.L.; Chung, H.; Tsai, H.-C.; Morgan, G.D.; Wille, G.W.; Young, C.

1996-01-01

To test the magnetohydrodynamic (MHD) pressure drop reduction performance of candidate insulator coatings for the ITER Vanadium/Lithium Breeding Blanket, a test section comprised of a V- 4Cr-4Ti liner inside a stainless steel pipe was designed and fabricated. Theoretically, the MHD pressure drop reduction benefit resulting, from an electrically insulating coating on a vanadium- lined pipe is identical to the benefit derived from an insulated pipe fabricated of vanadium alone. A duplex test section design consisting of a V alloy liner encased in a SS pressure boundary provided protection for vanadium from atmospheric contamination during operation at high temperature and obviated any potential problems with vanadium welding while also minimizing the amount of V alloy material required. From the MHD and insulator coating- point of view, the test section outer SS wall and inner V alloy liner can be modeled simply as a wall having a sandwich construction. Two 52.3 mm OD x 2.9 m long V-alloy tubes were fabricated by Century Tubes from 64 mm x 200 mm x 1245 mm extrusions produced by Teledyne Wah Chang. The test section's duplex structure was subsequently fabricated at Century Tubes by drawing down a SS pipe (2 inch schedule 10) over one of the 53.2 mm diameter V tubes
Effect of subcooling and wall thickness on pool boiling from downward-facing curved surfaces in water

Energy Technology Data Exchange (ETDEWEB)

El-Genk, M.S.; Glebov, A.G. [Univ. of New Mexico, Albuquerque, NM (United States)

1995-09-01

Quenching experiments were performed to investigate the effects of water subcooling and wall thickness on pool boiling from a downward-facing curved surface. Experiments used three copper sections of the same diameter (50.8 mm) and surface radius (148 mm), but different thickness (12.8, 20 and 30 mm). Local and average pool boiling curves were obtained at saturation and 5 K, 10 K, and 14 K subcooling. Water subcooling increased the maximum heat flux, but decreased the corresponding wall superheat. The minimum film boiling heat flux and the corresponding wall superheat, however, increased with increased subcooling. The maximum and minimum film boiling heat fluxes were independent of wall thickness above 20 mm and Biot Number > 0.8, indicating that boiling curves for the 20 and 30 thick sections were representative of quasi steady-state, but not those for the 12.8 mm thick section. When compared with that for a flat surface section of the same thickness, the data for the 12.8 mm thick section showed significant increases in both the maximum heat flux (from 0.21 to 0.41 MW/m{sup 2}) and the minimum film boiling heat flux (from 2 to 13 kW/m{sup 2}) and about 11.5 K and 60 K increase in the corresponding wall superheats, respectively.
Determination of a test section parameters for Iris nuclear reactor pressurizer

International Nuclear Information System (INIS)

Silva, Mario A.B. da; Lira, Carlos A.B. de O.

2009-01-01

An integral, modular and medium size nuclear reactor, known as IRIS, is being developed by Westinghouse and by research centers. IRIS is characterized by having most of its components inside the pressure vessel, eliminating the probability of accidents. Due to its integral configuration, there is no spray system for boron homogenization, which may cause power transients. Thus, boron mixing must be investigated. The aim of this paper is to establish the conditions under which a test section has to be built for boron dispersion analysis inside IRIS reactor pressurizer. Through Fractional Scaling Analysis, which is a new methodology of similarity, the main parameters for a test section are obtained. By combining Fractional Scaling Analysis with local scaling for the densimetric Froude number and a previously established volumetric scale factor, the values of recirculation orifices, inlet water temperature, time scale factor and recirculation flow for the test section (model) are determined so that boron distribution is well represented in IRIS reactor pressurizer (prototype). Analytical solutions were used to validate the adopted methodology and when the results simulated in the model are compared to those that characterize the prototype, the agreement for both systems is absolute. The thermal power also influences boron distribution inside the test section. This power is determined by condensation laws in the vapor region and by suitable correlations for free convection. The fractions for rising inlet recirculation water enthalpy and vapor formation are also considered. (author)
Compressor Calorimeter Test of R-404A Alternatives ARM-31a, D2Y-65, L-40, and R32 + R-134a Mixture using a Scroll Compressor

Energy Technology Data Exchange (ETDEWEB)

Shrestha, Som S [ORNL; Sharma, Vishaldeep [ORNL; Abdelaziz, Omar [ORNL

2013-08-01

As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares the performance of four lower-GWP alternative refrigerants, ARM-31a, D2Y-65, L-40, and R-32 + R-134a mixture, to that of refrigerant R-404A (baseline) in a scroll compressor designed for medium temperature refrigeration applications. These comparisons were carried out via compressor calorimeter tests performed on a compressor designed for refrigerant R-404A and having a nominal rated capacity of 23,500 Btu/hr. Tests were conducted over a suction dew point temperature range of -10 F to 35 F in 5 F increments and a discharge dew point temperature range of 70 F to 140 F in 10 F increments. All the tests were performed with 20 F superheat, 40 F superheat, and 65 F suction temperature. A liquid subcooling level of 10 F to 15 F was maintained for all the test conditions. However, the cooling capacities reported in this study are normalized for 0 F subcooling. The tests showed that the compressor energy efficiency ratio (EER) and cooling capacity with all four alternative refrigerants tested are higher at higher saturation suction and saturation discharge temperature and lower at lower saturation suction and saturation discharge temperature, compared to that of R-404A. Discharge temperatures of all the alternative refrigerants were higher than that of R-404A at all test conditions.
Finite Element Analysis and Test Results Comparison for the Hybrid Wing Body Center Section Test Article

Science.gov (United States)

Przekop, Adam; Jegley, Dawn C.; Rouse, Marshall; Lovejoy, Andrew E.

2016-01-01

This report documents the comparison of test measurements and predictive finite element analysis results for a hybrid wing body center section test article. The testing and analysis efforts were part of the Airframe Technology subproject within the NASA Environmentally Responsible Aviation project. Test results include full field displacement measurements obtained from digital image correlation systems and discrete strain measurements obtained using both unidirectional and rosette resistive gauges. Most significant results are presented for the critical five load cases exercised during the test. Final test to failure after inflicting severe damage to the test article is also documented. Overall, good comparison between predicted and actual behavior of the test article is found.
Demonstration tests for HTGR fuel elements and core components with test sections in HENDEL

Energy Technology Data Exchange (ETDEWEB)

Miyamoto, Yoshiaki; Hino, Ryutaro; Inagaki, Yoshiyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

1995-03-01

In the fuel stack test section (T{sub 1}) of the Helium Engineering Demonstration Loop (HENDEL), thermal and hydraulic performances of helium gas flows through a fuel rod channel and a fuel stack have been investigated for the High-Temperature Engineering Test Reactor (HTTR) core thermal design. The test data showed that the turbulent characteristics appearing in the Reynolds number above 2000: no typical behavior in the transition zone, and friction factors and heat transfer coefficients in the fuel channel were found to be higher than those in a smooth annular channel. Heat transfer behavior of gas flow in a fuel element channel with blockage and cross-flow through a gap between upper and lower fuel elements stacked was revealed using the mock-up models. On the other hand, demonstration tests have been performed to verify thermal and hydraulic characteristics and structural integrity related to the core bottom structure using a full-scale test facility named as the in-core structure test section (T{sub 2}). The sealing performance test revealed that the leakage of low-temperature helium gas through gaps between the permanent reflector blocks to the core was very low level compared with the HTTR design value and no change of the leakage flow rate were observed after a long term operation. The heat transfer tests including thermal transient at shutdown of gas circulators verified good insulating performance of core insulation structures in the core bottom structure and the hot gas duct; the temperature of the metal portion of these structure was below the design value. Examination of the thermal mixing characteristics indicated that the mixing of the hot helium gas started at a hot plenum and finished completely at downstream of the outlet hot gas duct. The present results obtained from these demonstration tests have been practically applied to the detailed design works and licensing procedures of the HTTR. (J.P.N.) 92 refs.
Ash particle erosion on steam boiler convective section

Energy Technology Data Exchange (ETDEWEB)

Meuronen, V

1998-12-31

In this study, equations for the calculation of erosion wear caused by ash particles on convective heat exchanger tubes of steam boilers are presented. A new, three-dimensional test arrangement was used in the testing of the erosion wear of convective heat exchanger tubes of steam boilers. When using the sleeve-method, three different tube materials and three tube constructions could be tested. New results were obtained from the analyses. The main mechanisms of erosion wear phenomena and erosion wear as a function of collision conditions and material properties have been studied. Properties of fossil fuels have also been presented. When burning solid fuels, such as pulverized coal and peat in steam boilers, most of the ash is entrained by the flue gas in the furnace. In bubbling and circulating fluidized bed boilers, particle concentration in the flue gas is high because of bed material entrained in the flue gas. Hard particles, such as sharp edged quartz crystals, cause erosion wear when colliding on convective heat exchanger tubes and on the rear wall of the steam boiler. The most important ways to reduce erosion wear in steam boilers is to keep the velocity of the flue gas moderate and prevent channelling of the ash flow in a certain part of the cross section of the flue gas channel, especially near the back wall. One can do this by constructing the boiler with the following components. Screen plates can be used to make the velocity and ash flow distributions more even at the cross-section of the channel. Shield plates and plate type constructions in superheaters can also be used. Erosion testing was conducted with three types of tube constructions: a one tube row, an in- line tube bank with six tube rows, and a staggered tube bark with six tube rows. Three flow velocities and two particle concentrations were used in the tests, which were carried out at room temperature. Three particle materials were used: quartz, coal ash and peat ash particles. Mass loss
Component Test Facility (Comtest) Phase 1 Engineering For 760°C (1400°F) Advanced Ultrasupercritical (A-USC) Steam Generator Development

Energy Technology Data Exchange (ETDEWEB)

Weitzel, Paul [Babcock & Wilcox Power Generation Group, Inc., Barberton, OH (United States)

2016-05-13

The Babcock & Wilcox Company (B&W) performed a Pre-Front End Engineering Design (Pre-FEED) of an A-USC steam superheater for a proposed component test program achieving 760°C (1400°F) steam temperature. This would lead to follow-on work in a Phase 2 and Phase 3 that would involve detail design, manufacturing, construction and operation of the ComTest. Phase 1 results have provided the engineering data necessary for proceeding to the next phase of ComTest. The steam generator superheater would subsequently supply the steam to an A-USC prototype intermediate pressure steam turbine. The ComTest program is important in that it will place functioning A-USC components in operation and in coordinated boiler and turbine service. It is also important to introduce the power plant operation and maintenance personnel to the level of skills required and provide the first background experience with hands-on training. The project will provide a means to exercise the complete supply chain events required in order to practice and perfect the process for A-USC power plant design, supply, manufacture, construction, commissioning, operation and maintenance. Representative participants will then be able to transfer knowledge and recommendations to the industry. ComTest is conceived in the manner of using a separate standalone plant facility that will not jeopardize the host facility or suffer from conflicting requirements in the host plant’s mission that could sacrifice the nickel alloy components and not achieve the testing goals. ComTest will utilize smaller quantities of the expensive materials and reduce the risk in the first operational practice for A-USC technology in the United States. Components at suitable scale in ComTest provide more assurance before putting them into practice in the full size A-USC demonstration plant.
Nonlinear Analysis and Preliminary Testing Results of a Hybrid Wing Body Center Section Test Article

Science.gov (United States)

Przekop, Adam; Jegley, Dawn C.; Rouse, Marshall; Lovejoy, Andrew E.; Wu, Hsi-Yung T.

2015-01-01

A large test article was recently designed, analyzed, fabricated, and successfully tested up to the representative design ultimate loads to demonstrate that stiffened composite panels with through-the-thickness reinforcement are a viable option for the next generation large transport category aircraft, including non-conventional configurations such as the hybrid wing body. This paper focuses on finite element analysis and test data correlation of the hybrid wing body center section test article under mechanical, pressure and combined load conditions. Good agreement between predictive nonlinear finite element analysis and test data is found. Results indicate that a geometrically nonlinear analysis is needed to accurately capture the behavior of the non-circular pressurized and highly-stressed structure when the design approach permits local buckling.
Sodium reflux pool-boiler solar receiver on-sun test results

Energy Technology Data Exchange (ETDEWEB)

Andraka, C E; Moreno, J B; Diver, R B; Moss, T A [Oak Ridge National Lab., TN (United States)

1992-06-01

The efficient operation of a Stirling engine requires the application of a high heat flux to the relatively small area occupied by the heater head tubes. Previous attempts to couple solar energy to Stirling engines generally involved directly illuminating the heater head tubes with concentrated sunlight. In this study, operation of a 75-kW{sub t} sodium reflux pool-boiler solar receiver has been demonstrated and its performance characterized on Sandia's nominal 75-kW{sub t} parabolic-dish concentrator, using a cold-water gas-gap calorimeter to simulate Stirling engine operation. The pool boiler (and more generally liquid-metal reflux receivers) supplies heat to the engine in the form of latent heat released from condensation of the metal vapor on the heater head tubes. The advantages of the pool boiler include uniform tube temperature, leading to longer life and higher temperature available to the engine, and decoupling of the design of the solar absorber from the engine heater head. The two-phase system allows high input thermal flux, reducing the receiver size and losses, therefore improving system efficiency. The receiver thermal efficiency was about 90% when operated at full power and 800{degree}C. Stable sodium boiling was promoted by the addition of 35 equally spaced artificial cavities in the wetted absorber surface. High incipient boiling superheats following cloud transients were suppressed passively by the addition of small amounts of xenon gas to the receiver volume. Stable boiling without excessive incipient boiling superheats was observed under all operating conditions. The receiver developed a leak during performance evaluation, terminating the testing after accumulating about 50 hours on sun. The receiver design is reported here along with test results including transient operations, steady-state performance evaluation, operation at various temperatures, infrared thermography, x-ray studies of the boiling behavior, and a postmortem analysis.
Experimental investigation of heat transfer in the transition region

International Nuclear Information System (INIS)

Johannsen, K.; Weber, P.; Feng, Q.

1990-10-01

An experimental study of forced convective boiling heat transfer for upflow of water in a circular tube has been performed using a heat transfer system with temperature-controlled indirect Joule heating. By this way, complete boiling curves from incipience of boiling to fully established film boiling could be measured including the transition boiling regime. The boiling curves were traversed in a quasi-steady mode, usually by increasing the set-point wall temperature average at a constant time rate of 3.5 K/min. The vast majority of results covers the pressure range from 0.1 to 1.0 MPa, mass flux range from 25 to 200 kg/(m 2 s) and inlet subcooling from 5 to 30 K. The experimental results of transition boiling heat transfer obtained in the centre of the test section were correlated in terms of a heat flux/surface superheat relationship that was normalized by the maximum heat flux (local CHF) and its associated wall superheat, respectively, to anchor the transition boiling curve to its low temperature limit. The upper surface temperature limit of the transition boiling regime was determined by inspection of measured axial distributions of surface heat flux and corresponding wall temperature. The critical heat flux (CHF) and its corresponding wall superheat has been measured, too. These temperature-controlled results were compared also with power-controlled experiments. The data are presented in terms of a table and accurate empirical correlations following Katto's generalized correlation scheme. Taking into account previous CHF data at L/D ≤ 100 and same range of flow conditions the length effect was found to further depend on pressure and mass flux. The data for the critical wall superheat show a distinct dependence upon pressure, mass flux and inlet quality that has not been observed before with comparable clarity
Long term steam oxidation of TP 347H FG in power plants

DEFF Research Database (Denmark)

Hansson, Anette Nørgaard; Korcakova, Leona; Hald, John

2005-01-01

The long term oxidation behaviour of TP 347H FG at ultra supercritical steam conditions was assessed by exposing the steel in test superheater loops in a Danish coal-fired power plant. The steamside oxide layer was investigated with scanning electron microscopy and energy dispersive Xray diffract......The long term oxidation behaviour of TP 347H FG at ultra supercritical steam conditions was assessed by exposing the steel in test superheater loops in a Danish coal-fired power plant. The steamside oxide layer was investigated with scanning electron microscopy and energy dispersive Xray...
UHV testing of spare straight section chambers of Indus-2

International Nuclear Information System (INIS)

Tiwari, S.K.; Ratnakala, K.C.; Sridhar, R.; Bhange, N.J.; Netram; Shukla, S.K.

2015-01-01

The vacuum system of Synchrotron Radiation Source, Indus-2, in RRCAT has been functioning up to the mark, continuously for last 10 years. To continue the same trouble-free functioning, it was planned to procure spares for all critical vacuum components, test for UHV performance and keep ready for installation, in case of requirement. As a part of this planning, fifteen chambers made of Aluminium alloy (6063 T6), procured as spare straight section chambers for Indus-2, and were tested for UHV performance. They were tested in batches of 2 or 3 chambers, depending upon their length, and the similar testing-procedure was followed. This paper narrates the tests carried out, and the results obtained. Ultimate vacuum in the range (2 to 9) x 10 -10 mbar was achieved. (author)
Cross sections, benchmarks, etc.: What is data testing all about

International Nuclear Information System (INIS)

Wagschal, J.; Yeivin, Y.

1985-01-01

In order to determine the consistency of two distinct measurements of a physical quantity, the discrepancy d between the two should be compared with its own standard deviation, σ = √(σ/sub 1//sup 2/+σ/sub 2//sup 2/). To properly test a given cross-section library by a set of benchmark (integral) measurements, the quantity corresponding to (d/σ)/sup 2/ is the quadratic d/sup dagger/C/sup -1/d. Here d is the vector of which the components are the discrepancies between the calculated values of the integral parameters and their corresponding measured values, and C is the uncertainty matrix of these discrepancies. This quadratic form is the only true measure of the joint consistency of the library and benchmarks. On the other hand, the very matrix C is essentially all one needs to adjust the library by the benchmarks. Therefore, any argument against adjustment simultaneously disqualifies all serious attempts to test cross-section libraries against integral benchmarks
Drop test and crash simulation of a civil airplane fuselage section

Directory of Open Access Journals (Sweden)

Liu Xiaochuan

2015-04-01

Full Text Available Crashworthiness of a civil airplane fuselage section was studied in this paper. Firstly, the failure criterion of a rivet was studied by test, showing that the ultimate tension and shear failure loads were obviously affected by the loading speed. The relations between the loading speed and the average ultimate shear, tension loads were expressed by two logarithmic functions. Then, a vertical drop test of a civil airplane fuselage section was conducted with an actual impact velocity of 6.85 m/s, meanwhile the deformation of cabin frame and the accelerations at typical locations were measured. The finite element model of a main fuselage structure was developed and validated by modal test, and the error between the calculated frequencies and the test ones of the first four modes were less than 5%. Numerical simulation of the drop test was performed by using the LS-DYNA code and the simulation results show a good agreement with that of drop test. Deforming mode of the analysis was the same as the drop test; the maximum average rigid acceleration in test was 8.81g while the calculated one was 9.17g, with an error of 4.1%; average maximum test deformation at four points on the front cabin floor was 420 mm, while the calculated one was 406 mm, with an error of 3.2%; the peak value of the calculated acceleration at a typical location was 14.72g, which is lower than the test result by 5.46%; the calculated rebound velocity result was greater than the test result 17.8% and energy absorption duration was longer than the test result by 5.73%.

Heavy Section Steel Technology Program. Part II. Intermediate vessel testing

International Nuclear Information System (INIS)

Whitman, G.D.

1975-01-01

The testing of the intermediate pressure vessels is a major activity under the Heavy Section Steel Technology Program. A primary objective of these tests is to develop or verify methods of fracture prediction, through the testing of selected structures and materials, in order that a valid basis can be established for evaluating the serviceability and safety of light-water reactor pressure vessels. These vessel tests were planned with sufficiently specific objectives that substantial quantitative weight could be given to the results. Each set of testing conditions was chosen so as to provide specific data by which analytical methods of predicting flaw growth, and in some cases crack arrest, could be evaluated. Every practical effort was made to assure that results would be relevant to some aspect of real reactor pressure vessel performance through careful control of material properties, selection of test temperatures, and design of prepared flaws. 5 references
Design of in-pile section monitoring system in fuel test loop

Energy Technology Data Exchange (ETDEWEB)

Sim, B. S.; Park, K. N.; Park, S. K.; Chi, D. Y.; Lee, J. M.; Ahn, S. H.; Lee, C. Y.; Kim, Y. J. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2005-07-01

In this paper a brief summary of the monitoring system of In-Pile Section(IPS) is described. To meet the user requirements on the test fuel and irradiation conditions, various instruments are installed on the test fuel pin itself and the appropriate locations in IPS. The requirements and descriptions for instruments, gas supply system, and the data acquisition system to sample and record parameters are described.
Experiments on HFE-7100 pool boiling at atmospheric pressure in horizontal narrow spaces

Energy Technology Data Exchange (ETDEWEB)

Guglielmini, G.; Misale, M.; Priarone, A. [Universita degli Studi di Genova (Italy). DIPTEM - Sezione di Termoenergetica e Condizionamento Ambientale

2009-07-01

Experiments were performed to examine the pool boiling heat transfer and critical heat flux on a smooth copper circular surface, confined by a face-to-face parallel unheated surface, by changing the gap between the surfaces and the unheated surface diameter. Pool boiling data at atmospheric pressure were obtained for saturated HFE-7100. The gap values investigated, between the boiling surface and the adiabatic one, were s 0.5, 1.0, 2.0, 3.5 mm. To confine the boiling surface, two different Plexiglas plates were used: the former characterised by a diameter D = 60 mm, large as the overall test section support, the latter characterised by a diameter D = 30 mm, large to cover only copper boiling surface (d = 30 mm). For each configuration, boiling curves were obtained up to the thermal crisis. For both different types of confinement, it was observed that the boiling curves match at low wall superheat, except for s = 0.5 mm, 1 mm. However, at high wall superheat, a drastic reduction in heat transfer as well as CHF appears decreasing the channel width s; for all gap sizes, this reduction is less pronounced for the smaller confinement wall (D = 30 mm). Instead, at low wall superheat for gap of 0.5 and 1.0 mm, the heat transfer coefficient is higher for diameter disc of 60 mm. CHF data were also compared with a literature correlation (Misale and al., 2009). (author)
Design Improvement of Double Pressure Vessel in the In-pile Test Section

Energy Technology Data Exchange (ETDEWEB)

Hong, Jintae; Heo, Sung-Ho; Joung, Chang-Young; Kim, Ka-Hye [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-10-15

To carry out an irradiation test of nuclear fuels, a nuclear fuel test rig should be fabricated and installed in the in-pile test section (IPS), which is installed in the reactor hall. While carrying out an irradiation test, sealing out coolant which passes through the test rig is one of the most important issues. In particular, although the double pressure vessel is assembled with the IPS head by two o-rings and six bolts, 15.5 MPa of highly pressurized coolant leaks through the gap between the vessel and IPS head. Because the temperature of the coolant in the test loop is 300 .deg. C , and the pool of HANARO is 40 .deg. C, the double pressure vessel is necessary to insulate them. Therefore, a new design to prevent the leakage of coolant needs to be developed. In this study, EB welding technique is considered to assemble the double pressure vessel and the IPS head, and their mechanical design is modified to enable the welding process. In this study, an improved design for sealing out the coolant at the pressure boundary between the double pressure vessel and the IPS head has been developed. An EB weld is applied to seal out the pressure boundary, and its sealing performance is verified by NDE, a cross section test, and a hydraulic pressure test. From the verification test results, the improved design can be used in fabricating the IPS for a nuclear fuel irradiation test.
Simulation of Model Force-Loading with Changing Its Position in the Wind Tunnel Test Section

Directory of Open Access Journals (Sweden)

V. T. Bui

2015-01-01

Full Text Available When planning and implementing an aerodynamic experiment, model sizes and its position in the test section of the wind tunnel (WT play very important role. The paper focuses on the value variations of the aerodynamic characteristics of a model through changing its position in the WT test section and on the attenuation of the velocity field disturbance in front of the model. Flow around aerodynamic model profile in the open test section of the low-speed WT T-500 is simulated at BMSTU Department SM3. The problem is solved in a two-dimensional case using the ANSYS Fluent package. The mathematical model of flow is based on the Reynolds equations closed by the SST turbulence model. The paper also presents the results of the experiment. Experiments conducted in WT T-500 well correlate with the calculated data and show the optimal position in the middle of the test section when conducting the weighing and drainage experiments. Disturbance of tunnel dynamic pressure (velocity head and flow upwash around the model profile and circular cylinder in the WT test section is analyzed. It was found that flow upstream from the front stagnation point on the body weakly depends on the Reynolds number and obtained results can be used to assess the level of disturbances in the flow around a model by incompressible airflow.
New Tools to Prepare ACE Cross-section Files for MCNP Analytic Test Problems

International Nuclear Information System (INIS)

Brown, Forrest B.

2016-01-01

Monte Carlo calculations using one-group cross sections, multigroup cross sections, or simple continuous energy cross sections are often used to: (1) verify production codes against known analytical solutions, (2) verify new methods and algorithms that do not involve detailed collision physics, (3) compare Monte Carlo calculation methods with deterministic methods, and (4) teach fundamentals to students. In this work we describe 2 new tools for preparing the ACE cross-section files to be used by MCNP ® for these analytic test problems, simple a ce.pl and simple a ce m g.pl.
Integral test on activation cross section of tag gas nuclides using fast neutron spectrum fields

Energy Technology Data Exchange (ETDEWEB)

Aoyama, Takafumi; Suzuki, Soju [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

1997-03-01

Activation cross sections of tag gas nuclides, which will be used for the failed fuel detection and location in FBR plants, were evaluated by the irradiation tests in the fast neutron spectrum fields in JOYO and YAYOI. The comparison of their measured radioactivities and the calculated values using the JENDL-3.2 cross section set showed that the C/E values ranged from 0.8 to 2.8 for the calibration tests in YAYOI and that the present accuracies of these cross sections were confirmed. (author)
Equilibrium quality and mass flux distributions in an adiabatic three-subchannel test section

International Nuclear Information System (INIS)

Yadigaroglu, G.; Maganas, A.

1993-01-01

An experiment was designed to measure the fully-developed quality and mass flux distributions in an adiabatic three-subchannel test section. The three subchannels had the geometrical characteristics of the corner, side, and interior subchannels of a BWR-5 rod bundle. Data collected with Refrigerant-144 at pressures ranging from 7 to 14 bar, simulating operation with water in the range 55 to 103 bar are reported. The average mass flux and quality in the test section were in the ranges 1300 to 1750 kg/m s and -0.03 to 0.25, respectively. The data are analyzed and presented in various forms
The cryogenic pumping section of KATRIN and the test experiment TRAP

CERN Document Server

Eichelhardt, F

2011-01-01

The Karlsruhe Tritium Neutrino experiment (KATRIN) employs a Cryogenic Pumping Section (CPS) at ~ 4.5 K to suppress the tritium penetration into the spectrometers. A test experiment (TRAP - Tritium Argon frost Pump) has been set up to investigate the tritium pumping performance of the CPS.
Sectional pipeline bundles. Design, fabrication and testing of a subsea pipeline connection system

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-08-01

The tests of the prototype system indicated that the system is applicable for connecting pipeline bundle sections. The overall performance of the system is therefore concluded to be satisfactory. Some modifications are required though, for improving the reliability of the system to the level required for offshore North Sea application. The tests showed that connection of the pipeline bundle sections can be performed for alignment tolerances larger than those expected during a typical subsea installation. Pull-in of bundle end sections can be performed with pull-in wires deployed from surface. The offshore tests showed that handling of wires must be done with great care to avoid possibility for wire entanglement, especially if a fully diverless system is to be used. The flowline connection tool was found to be suitable for final alignment of the individual spool ends. It was demonstrated that face to face contact between the hub faces in the connector was obtained after tie-in. Pressure tests showed that the connector could be sealed by the tie-in force applied by the connection tool tie-in system. However, the standard connector clamp which was used, was found to be insuficient for maintaining the connector effectively sealed after removal of the pull-in force applied by the connection tool. Based on the results proposals for improvements of the system are included. Improvements are applicable to the current system for connection of bundle sections or for tie-in operations, relating to conventional pipelines. The improvements also includes a strong connection clamp suitable for subsea use. The connection clamp will replace the standard clamp devise used in this project. (au) EFP-96. 41 refs.
Equilibrium quality and mass flux distributions in an adiabatic three-subchannel test section

International Nuclear Information System (INIS)

Yadigaroglu, G.; Maganas, A.

1995-01-01

An experiment was designed to measure the fully developed quality and mass flux distributions in an adiabatic three-subchannel test section. The three subchannels had the geometrical characteristics of the corner, side, and interior subchannels of a boiling water reactor (BWR-5) rod bundle. Data collected with Refrigerant-114 at pressures ranging from 7 to 14 bars, simulating operation with water in the range 55 to 103 bars are reported. The average mass flux and quality in the test section were in the ranges 1,300 to 1,750 kg/m 2 · s and -0.03 to 0.25, respectively. The data are analyzed and presented in various forms
Advanced steam cycles for light water reactors. Final report

International Nuclear Information System (INIS)

Mitchell, R.C.

1975-07-01

An appraisal of the potential of adding superheat to improve the overall LWR plant cycle performance is presented. The study assesses the economic and technical problems associated with the addition of approximately 500 0 F of superheat to raise the steam temperature to 1000 0 F. The practicality of adding either nuclear or fossil superheat to LWR's is reviewed. The General Electric Company Boiling Water Reactor (BWR) model 238-732 (BWR/6) is chosen as the LWR starting point for this evaluation. The steam conditions of BWR/6 are representative of LWR's. The results of the fossil superheat portion of the evaluation are considered directly applicable to all LWR's. In spite of the potential of a nuclear superheater to provide a substantial boost to the LWR cycle efficiency, nuclear superheat offers little promise of development at this time. There are difficult technical problems to resolve in the areas of superheat fuel design and emergency core cooling. The absence of a developed high integrity, high temperature fuel for operation in the steam/water environment is fundamental to this conclusion. Fossil superheat offers the potential opportunity to utilize fossil fuel supplies more efficiently than in any other mode of central station power generation presently available. Fossil superheat topping cycles evaluated included atmospheric fluidized beds (AFB), pressurized fluidized beds, pressurized furnaces, conventional furnaces, and combined gas/steam turbine cycles. The use of an AFB is proposed as the preferred superheat furnace. Fossil superheat provides a cycle efficiency improvement for the LWR of two percentage points, reduces heat rejection by 15 percent per kWe generated, increases plant electrical output by 54 percent, and burns coal with an incremental net efficiency of approximately 40 percent. This compares with a net efficiency of 36--37 percent which might be achieved with an all-fluidized bed fossil superheat plant design
Experimental Investigation of Tensile Test on Connection of Cold-formed Cut-curved Steel Section

Science.gov (United States)

Sani, Mohd Syahrul Hisyam Mohd; Muftah, Fadhluhartini; Rahman, Nurul Farraheeda Abdul; Fakri Muda, Mohd

2017-08-01

Cold-formed steel (CFS) is widely used as structural and non-structural components such as roof trusses and purlin. A CFS channel section with double intermediate web stiffener and lipped is chosen based on the broader usage in roof truss construction. CFS section is cut to form cold-formed pre-cut-curved steel section and lastly strengthened by several types of method or likely known as connection to establish the cold-formed cut-curved steel (CFCCS) section. CFCCS is proposed to be used as a top chord section in the roof truss system. The CFCCS is to resist the buckling phenomena of the roof truss structure and reduced the compression effect on the top chord. The tensile test connection of CFCCS section, especially at the flange element with eight types of connection by welding, plate with self-drilling screw and combination is investigated. The flange element is the weakest part that must be solved first other than the web element because they are being cut totally, 100% of their length for curving process. The testing is done using a universal testing machine for a tensile load. From the experiment, specimen with full welding has shown as a good result with an ultimate load of 13.37 kN and reported having 35.41% when compared with normal specimen without any of connection methods. Furthermore, the experimental result is distinguished by using Eurocode 3. The failure of a full welding specimen is due to breaking at the welding location. Additionally, all specimens with either full weld or spot weld or combination failed due to breaking on weld connection, but specimen with flange plate and self-drilling screw failed due to tilting and bearing. Finally, the full welding specimen is chosen as a good connection to perform the strengthening method of CFCCS section.
Optimised design and thermal-hydraulic analysis of the IFMIF/HFTM test section

Energy Technology Data Exchange (ETDEWEB)

Gordeev, S.; Heinzel, V.; Lang, K.H.; Moeslang, A.; Schleisiek, K.; Slobodtchouk, V.; Stratmanns, E.

2003-10-01

On the basis of previous concepts, analyses and experiments, the high flux test module (HFTM) for the International Fusion Materials Irradiation Facility (IFMIF) was further optimised. The work focused on the design and the thermal hydraulic analysis of the HFTM section containing the material specimens to be irradiated, the ''test section'', with the main objective to improve the concept with respect to the optimum use of the available irradiation volume and to the temperature of the specimens. Particular emphasis was laid on the application of design principles which assure stable and reproducible thermal conditions. The present work has confirmed the feasibility and suitability of the optimised design of the HFTM test section with chocolate plate like shaped rigs. In particular it has been shown that the envisaged irradiation temperatures can be reached with acceptable temperature differences inside the specimen stack. The latter can be achieved only by additional electrical heating of the axial ends of the capsules. Division of the heater in three sections with separate power supply and control units is necessary. Maintaining of the temperatures during beam-off periods likewise requires electrical heating. The required electrical heaters - mineral isolated wires - are commercially available. The potential of the CFD code STAR-CD for the thermal hydraulic analysis of complex systems like the HFTM was confirmed. Nevertheless, experimental confirmation is desirable. Suitable experiments are under preparation. To verify the assumptions made on the thermal conductivity of the contact faces and layers between the two shells of the rig, dedicated experiments are suggested. The present work must be complemented by a thermal mechanical analysis of the module. Most critical component in this respect seems to be the rig wall. Furthermore, it will be necessary to investigate the response of the HFTM to power transients, and to determine the requirements
Optimised design and thermal-hydraulic analysis of the IFMIF/HFTM test section

International Nuclear Information System (INIS)

Gordeev, S.; Heinzel, V.; Lang, K.H.; Moeslang, A.; Schleisiek, K.; Slobodtchouk, V.; Stratmanns, E.

2003-10-01

On the basis of previous concepts, analyses and experiments, the high flux test module (HFTM) for the International Fusion Materials Irradiation Facility (IFMIF) was further optimised. The work focused on the design and the thermal hydraulic analysis of the HFTM section containing the material specimens to be irradiated, the ''test section'', with the main objective to improve the concept with respect to the optimum use of the available irradiation volume and to the temperature of the specimens. Particular emphasis was laid on the application of design principles which assure stable and reproducible thermal conditions. The present work has confirmed the feasibility and suitability of the optimised design of the HFTM test section with chocolate plate like shaped rigs. In particular it has been shown that the envisaged irradiation temperatures can be reached with acceptable temperature differences inside the specimen stack. The latter can be achieved only by additional electrical heating of the axial ends of the capsules. Division of the heater in three sections with separate power supply and control units is necessary. Maintaining of the temperatures during beam-off periods likewise requires electrical heating. The required electrical heaters - mineral isolated wires - are commercially available. The potential of the CFD code STAR-CD for the thermal hydraulic analysis of complex systems like the HFTM was confirmed. Nevertheless, experimental confirmation is desirable. Suitable experiments are under preparation. To verify the assumptions made on the thermal conductivity of the contact faces and layers between the two shells of the rig, dedicated experiments are suggested. The present work must be complemented by a thermal mechanical analysis of the module. Most critical component in this respect seems to be the rig wall. Furthermore, it will be necessary to investigate the response of the HFTM to power transients, and to determine the requirements on the electrical
Analytical Work in Support of the Design and Operation of Two Dimensional Self Streamlining Test Sections

Science.gov (United States)

Judd, M.; Wolf, S. W. D.; Goodyer, M. J.

1976-01-01

A method has been developed for accurately computing the imaginary flow fields outside a flexible walled test section, applicable to lifting and non-lifting models. The tolerances in the setting of the flexible walls introduce only small levels of aerodynamic interference at the model. While it is not possible to apply corrections for the interference effects, they may be reduced by improving the setting accuracy of the portions of wall immediately above and below the model. Interference effects of the truncation of the length of the streamlined portion of a test section are brought to an acceptably small level by the use of a suitably long test section with the model placed centrally.
Investigation of steam oxidation behaviour of TP347H FG Part 2: Exposure at 91 bar

DEFF Research Database (Denmark)

Jianmin, J; Montgomery, Melanie; Larsen, OH

2005-01-01

Tube specimens of TP347FG were exposed in a test superheater loop in a biomass plant in Denmark. The specimens were exposed to surface metal temperatures in the range of 455-568C, steam pressure of 91 bar and exposure duration of 3500 and 8700 hours. The oxide thickness and morphology was investi......Tube specimens of TP347FG were exposed in a test superheater loop in a biomass plant in Denmark. The specimens were exposed to surface metal temperatures in the range of 455-568C, steam pressure of 91 bar and exposure duration of 3500 and 8700 hours. The oxide thickness and morphology...
Analysis of a Hybrid Wing Body Center Section Test Article

Science.gov (United States)

Wu, Hsi-Yung T.; Shaw, Peter; Przekop, Adam

2013-01-01

The hybrid wing body center section test article is an all-composite structure made of crown, floor, keel, bulkhead, and rib panels utilizing the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) design concept. The primary goal of this test article is to prove that PRSEUS components are capable of carrying combined loads that are representative of a hybrid wing body pressure cabin design regime. This paper summarizes the analytical approach, analysis results, and failure predictions of the test article. A global finite element model of composite panels, metallic fittings, mechanical fasteners, and the Combined Loads Test System (COLTS) test fixture was used to conduct linear structural strength and stability analyses to validate the specimen under the most critical combination of bending and pressure loading conditions found in the hybrid wing body pressure cabin. Local detail analyses were also performed at locations with high stress concentrations, at Tee-cap noodle interfaces with surrounding laminates, and at fastener locations with high bearing/bypass loads. Failure predictions for different composite and metallic failure modes were made, and nonlinear analyses were also performed to study the structural response of the test article under combined bending and pressure loading. This large-scale specimen test will be conducted at the COLTS facility at the NASA Langley Research Center.
Lexical patterns in the reading comprehension section of the toefl test

Directory of Open Access Journals (Sweden)

Fabiana Macmillan

2006-11-01

Full Text Available The TOEFL (Test of English as a Foreign Language is currently one of the most widely accepted English language proficiency tests. Designed by the ETS (Educational Testing Service, the main purpose of the TOEFL is to determine whether the English language skills of a student applying to a North American college or university are adequate for enrollment into the selected program of study. This study will focus upon the third section of the TOEFL, Reading Comprehension, which consists of several passages followed by questions with different testing purposes. An adaptation of Hoey's (1991 analytical system for the analysis of lexical cohesion in authentic texts will be used to identify bonds connecting reading comprehension questions on the test to key excerpts in the passages they are related to. A number of sample reading comprehension questions taken from practice tests produced by the ETS will be analyzed. The analysis will focus on the relationship between the testing purpose of each question and the type(s of lexical link involved in the identification of the correct answer.
Problems With Section Two ITP TOEFL Test

Directory of Open Access Journals (Sweden)

Rizki Ananda

2016-03-01

Full Text Available This study was designed to investigate (1 the difficulties faced by EFL university students with section two of the ITP, and (2 whether part A or part B was more difficult for them and why. A number of 26 students from two different universities, Syiah Kuala University and the State Islamic University Ar-Raniry were the samples for the test. The data was obtained from a multiple choice questionnaire test consisting of 46 questions, each with 4 answers to choose from. The results showed that inversions (12%, subject-verb agreements (10%, adverb clause connectors (7%, passives (6%, reduced adjective clauses (5%, parallel structures (5% and use of verbs (5% were the most difficult questions for the students. Furthermore, they felt that part B was more difficult than part A, as finding an error in a sentence was harder than completing a sentence from a multiple choice. Furthermore, the length of questions in part A did not affect the amount of time the students spent to complete part A and did not cause them to panic. Also, unfamiliar words in part A were not regarded as a problem by the students. Hence, TOEFL teachers and trainers are highly encouraged to pay more attention to doing study exercises for the seven topics with the highest percentages above in part A and also to more practice for part B.

Effect of condensable species on particulate fouling

NARCIS (Netherlands)

Sathyanarayanarao Subbarao, K.K.; Rindt, C.C.M.; Steenhoven, van A.A.; Malayeri, M.R.; Muller-Steinhagen, H.; Watkinson, A.P.

2011-01-01

The flue gases emanating from the combustion of fuels or gasification process invariably comprises particulate matter and many chemical species in vapor form. The temperature of the flue gases gradually reduces when passing through different sections of heat exchanger like superheater, evaporator
Effect of condensable species on particulate fouling

NARCIS (Netherlands)

Sathyanarayanarao Subbarao, K.K.; Rindt, C.C.M.; Steenhoven, van A.A.

2013-01-01

The flue gases emanating from the combustion of fuels or gasification process invariably comprise particulate matter and many chemical species in vapor form. The temperature of the flue gases gradually reduces when passing through different sections of heat exchanger, such as the superheater,
A worked example using the SP249 advanced assessment route: the carregado unit 6 final superheater outlet header

Energy Technology Data Exchange (ETDEWEB)

Brear, J.M.; Jarvis, P.; Jones, G.T. [ERA Technology (United Kingdom); Jovanovic, A.S.; Friemann, M.; Kluttig, B.; Ober, M. [Stuttgart Univ. (Germany). Staatliche Materialpruefungsanstalt; Batista, A. [EDP-PROET (Portugal); Araujo, C.L. de; Pires, A. [ISQ (Portugal)

1995-12-31

As a key part of its information resource, the SP249 Project contains a number of case studies, drawn from the collective experience of the partners and from the literature. The user of the system may search this data-base by component type and material or by assessment method, to find a practical example close to his own current problem. He can thus draw upon past experience as well as state-of-the-art knowledge to obtain advice. To facilitate this, a set of key-words has been defined to create links between the case studies and the overall assessment methodology. These relate to damage and failure types and causes as well as to techniques of investigation and assessment. For demonstration, validation and didactic purposes, certain of these case studies - one per end-user utility in the project - have been chosen for full elaboration as `worked-examples`. These real component evaluations are worked through by an expert group from the project team so as to provide the utility staff with `hands-on` training in both the practical techniques of component life. The assessment and the use of the knowledge based system. The exercise also provides valuable opportunity for feedback, allowing refinement of the technology package and the software. Amongst these worked examples, an assessment of EDP`s Carregado Unit 6 Final Superheater Outlet Header has been chosen for special attention - as the operators have kindly allowed direct CSS to the component during two outages. This article summarises the Carregado Case Study. It is intended to serve as a demonstration and as to how the Advanced Assessment Route (AAR) is used in practice. The actions performed and results obtained are summarised
Experimental evaluation of wall Mach number distributions of the octagonal test section proposed for NASA Lewis Research Center's altitude wind tunnel

Science.gov (United States)

Harrington, Douglas E.; Burley, Richard R.; Corban, Robert R.

1986-01-01

Wall Mach number distributions were determined over a range of test-section free-stream Mach numbers from 0.2 to 0.92. The test section was slotted and had a nominal porosity of 11 percent. Reentry flaps located at the test-section exit were varied from 0 (fully closed) to 9 (fully open) degrees. Flow was bled through the test-section slots by means of a plenum evacuation system (PES) and varied from 0 to 3 percent of tunnel flow. Variations in reentry flap angle or PES flow rate had little or no effect on the Mach number distributions in the first 70 percent of the test section. However, in the aft region of the test section, flap angle and PES flow rate had a major impact on the Mach number distributions. Optimum PES flow rates were nominally 2 to 2.5 percent wtih the flaps fully closed and less than 1 percent when the flaps were fully open. The standard deviation of the test-section wall Mach numbers at the optimum PES flow rates was 0.003 or less.
Four-Point Bending Strength Testing of Pultruded Fiberglass Composite Wind Turbine Blade Sections

International Nuclear Information System (INIS)

Musial, W.; Bourne, B; Hughes, S; Zuteck, M. D.

2001-01-01

The ultimate strength of the PS Enterprises pultruded blade section was experimentally determined under four-point bending at the National Renewable Energy Laboratory. Thirteen 8-foot long full-scale blade segments were individually tested to determine their maximum moment carrying capability. Three airfoil-bending configurations were tested: high- and low-pressure skin buckling, and low pressure skin buckling with foam interior reinforcement. Maximum strain was recorded for each sample on the compressive and tensile surfaces of each test blade. Test data are compared to the results of three analytical buckling prediction methods. Based on deviations from the linear strain versus load curve, data indicate a post-buckling region. High-pressure side buckling occurred sooner than low-pressure side buckling. The buckling analyses were conservative for both configurations, but high-pressure side buckling in particular was substantially under-predicted. Both high- and low-pressure buckling configurations had very similar failure loads. These results suggests that a redundant load path may be providing strength to the section in the post-buckling region, making the onset of panel buckling a poor predictor of ultimate strength for the PS Enterprises pultrusion
Study of the thermal and hydraulic phenomena occurring during power excursion on a heated test section

International Nuclear Information System (INIS)

Nyer, M.

1969-01-01

The thermal and hydrodynamic phenomena occurring during a power excursion were studied in an out-of-pile loop with a water cooled channel at low pressure (1 to 4 atm. abs. ). Circular and rectangular test sections with electrically heated walls of two different thermal diffusivity materials(aluminium and stainless steel) were used. The rectangular test sections were 600 mm long, 35 mm wide and had a 2, 9 mm gap; they simulate two half plates of the M.T.R. fuel element. Natural or forced convection are possible in the test section; the water height above it can be varied from 2.8 to 8 meters and the maximum allowed pressure at its outlet is 4 atm. abs.The heating source is a series of lead batteries which is able to generate, for short periods of time, 85 volts and 25000 amperes; linear, square or exponential power rise versus time can be realized. A 14 channels tape recorder (0-10 000 Hz bandwidth; is used for the measurements of temperature (8/100 mm diameter thermocouple), pressure ('Statham' pressure transducers) and void fraction (X rays). More than 500 tests have been carried out. The influence of the initial water temperature, flow rate, pressure, water height on the water ejections, pressure variations and void fraction in the test section were studied. Tests with energies up to 3000 W/cm in 50 milliseconds were attempted. The energy above which the instabilities appear was determined. An interpretation of the observed phenomena and a simplified theoretical model are presented [fr
Heavy-Section Steel Technology Program intermediate-scale pressure vessel tests

International Nuclear Information System (INIS)

Bryan, R.H.; Merkle, J.G.; Smith, G.C.; Whitman, G.D.

1977-01-01

The tests of intermediate-size vessels with sharp flaws permitted the comparison of experimentally observed behavior with analytical predictions of the behavior of flawed pressure vessels. Fracture strains estimated by linear elastic fracture mechanics (LEFM) were accurate in the cases in which the flaws resided in regions of high transverse restraint and the fracture toughness was sufficiently low for unstable fracture to occur prior to yielding through the vessel wall. When both of these conditions were not present, unstable fracture did occur, always preceded by stable crack growth; and the cylinders with flaws initially less than halfway through the wall attained gross yield prior to burst. Predictions of failure pressure of the vessels with flawed nozzles, based upon LEFM estimates of failure strain, were very conservative. LEFM calculations of critical load were based upon small-specimen fracture toughness test data. Whenever gross yielding preceded failure, the actual strains achieved were considerably greater than the estimated strains at failure based on LEFM. In such cases the strength of the vessel may be no longer dependent upon plane-strain fracture toughness but upon the capacity of the cracked section to carry the imposed load stably in the plastic range. Stable crack growth, which has not been predictable quantitatively, is an important factor in elastic-plastic analysis of strength. The ability of the flawed vessels to attain gross yield in unflawed sections has important qualitative implications on pressure vessel safety margins. The gross yield condition occurs in light-water-reactor pressure vessels at about 2 x design pressure. The intermediate vessel tests that demonstrated a capacity for exceeding this load confirm that the presumed margin of safety is not diminished by the presence of flaws of substantial size, provided that material properties are adequate
Construction of experimental HMA test sections in order to monitor the compaction process

NARCIS (Netherlands)

ter Huerne, Henderikus L.; Molenaar, A.A.A.; van de Ven, M.F.C.

2003-01-01

For getting better understanding about the process of HMA compaction, a test section was constructed while the governing process parameters, like; compaction progress, temperature of the material at which activities were employed, equipment properties and meteorological circumstances, were
Testing for Unit Roots in Small Panels with Short-run and Long-run Cross-sectional Dependencies

OpenAIRE

Yoosoon Chang; Wonho Song

2009-01-01

An IV approach, using as instruments non-linear transformations of the lagged levels, is explored to test for unit roots in panels with general dependency and heterogeneity across cross-sectional units. We allow not only for the cross-sectional dependencies of innovations, but also for the presence of co-integration across cross-sectional levels. Unbalanced panels and panels with differing individual short-run dynamics and cross-sectionally related dynamics are also permitted. We also more ca...
Dynamic Response of a 50 kW Organic Rankine Cycle System in Association with Evaporators

Directory of Open Access Journals (Sweden)

Yuh-Ren Lee

2014-04-01

Full Text Available The influences of various evaporators on the system responses of a 50 kW ORC system using R-245fa are investigated in this study. First the effect of the supplied hot water flowrate into the evaporator is examined and the exit superheat on the system performance between plate and shell-and-tube evaporator is also reported. Test results show that the effect of hot water flowrate on the evaporator imposes a negligible effect on the transient response of the ORC system. These results prevail even for a 3.5-fold increase of the hot water flowrate and the system shows barely any change subject to this drastic hot water flowrate change. The effect of exit superheat on the ORC system depends on the type of the evaporator. For the plate evaporator, an exit superheat less than 10 °C may cause ORC system instability due to considerable liquid entrainment. To maintain a stable operation, the corresponding Jakob number of the plate heat evaporator must be above 0.07. On the other hand, by employing a shell and tube heat evaporator connected to the ORC system, no unstable oscillation of the ORC system is observed for exit superheats ranging from 0 to 17 °C.
Benchmark experiments to test plutonium and stainless steel cross sections. Topical report

International Nuclear Information System (INIS)

Jenquin, U.P.; Bierman, S.R.

1978-06-01

The Nuclear Regulatory Commission (NRC) commissioned Battelle, Pacific Northwest Laboratory (PNL) to ascertain the accuracy of the neutron cross sections for the isotopes of plutonium and the constituents of stainless steel and determine if improvements can be made in application to criticality safety analysis. NRC's particular area of interest is in the transportation of light-water reactor spent fuel assemblies. The project was divided into two tasks. The first task was to define a set of integral experimental measurements (benchmarks). The second task is to use these benchmarks in neutronics calculations such that the accuracy of ENDF/B-IV plutonium and stainless steel cross sections can be assessed. The results of the first task are given in this report. A set of integral experiments most pertinent to testing the cross sections has been identified and the code input data for calculating each experiment has been developed
Reliability of the Balance Evaluation Systems Test (BESTest) and BESTest sections for adults with hemiparesis

Science.gov (United States)

Rodrigues, Letícia C.; Marques, Aline P.; Barros, Paula B.; Michaelsen, Stella M.

2014-01-01

BACKGROUND: The Balance Evaluation Systems Test (BESTest) was recently created to allow the development of treatments according to the specific balance system affected in each patient. The Brazilian version of the BESTest has not been specifically tested after stroke. OBJECTIVE: To evaluate the intra- and inter-rater reliability and concurrent and convergent validity of the total score of the BESTest and BESTest sections for adults with hemiparesis after stroke. METHOD: The study included 16 subjects (61.1±7.5 years) with chronic hemiparesis (54.5±43.5 months after stroke). The BESTest was administered by two raters in the same week and one of the raters repeated the test after a one-week interval. Intraclass correlation coefficient (ICC) was calculated to assess intra- and interrater reliability. Concurrent validity with the Berg Balance Scale (BBS) and convergent validity with the Activities-specific Balance Confidence scale (ABC-Brazil) were assessed using Pearson's correlation coefficient. RESULTS: Both the BESTest total score (ICC=0.98) and the BESTest sections (ICC between 0.85 and 0.96) have excellent intrarater reliability. Interrater reliability for the total score was excellent (ICC=0.93) and, for the sections, it ranged between 0.71 and 0.94. The correlation coefficient between the BESTest and the BBS and ABC-Brazil were 0.78 and 0.59, respectively. CONCLUSIONS: The Brazilian version of the BESTest demonstrated adequate reliability when measured by sections and could identify what balance system was affected in patients after stroke. Concurrent validity was excellent with the BBS total score and good to excellent with the sections. The total scores but not the sections present adequate convergent validity with the ABC-Brazil. However, other psychometric properties should be further investigated. PMID:25003281
Commissioning of the Ground Test Accelerator Intertank Matching Section

International Nuclear Information System (INIS)

Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Cole, R.; Connolly, R.; Gilpatrick, J.D.; Ingalls, W.B.; Kersteins, D.; Little, C.; Lohsen, R.A.; Lysenko, W.P.; Mottershead, C.T.; Power, J.; Rusthoi, D.P.; Sandoval, D.P.; Stevens, R.R.; Vaughn, G.; Wadlinger, E.A.; Weiss, R.; Yuan, V.

1992-01-01

The Ground Test Accelerator (GTA) has the objective of verifying much of the technology (physics and engineering) required for producing high-brightness, high-current H - beams. GTA commissioning is staged to verify the beam dynamics design of each major accelerator component as it is brought on-line. The commissioning stages are the 35 keV H - injector, the 2.5 MeV Radio Frequency Quadrupole (RFQ), the Intertank Matching Section (IMS), the 3.2 MeV first 2βγ Drift Tube Linac (DTL-1) module, the 8.7 MeV 2βγ DTL (modules 1--5), and the 24 MeV GTA; all 10 DTL modules. Commissioning results from the IMS beam experiments will be presented
A phenomenological model of the thermal-hydraulics of convective boiling during the quenching of hot rod bundles: Part 2, Assessment of the model with steady-state and transient post-CHF data

International Nuclear Information System (INIS)

Unal, C.; Nelson, R.

1991-01-01

After completing the thermal-hydraulic model developed in a companion paper, we performed assessment calculations of the model using steady-state and transient post-critical heat flux (CHF) data. This paper discusses the results of those calculations. The hot-patch model, in conjunction with the other thermal-hydraulic models, was capable of modeling the Winfrith post-CHF hot-patch experiments. The hot-patch model kept the wall temperatures at the specified levels in the hot-patch regions and did not allow any quench-front propagation from either the bottom or the top of the test section. Among the four Winfrith runs selected to assess the hot-patch model, the average deviation in hot-patch power predictions was 15.4%, indicating reasonable predictions of the amount of energy transferred to the fluid by the hot patch. The interfacial heat-transfer model tended to slightly under-predict the vapor temperatures. The maximum difference between calculated and measured vapor superheats was 20%, with a 10% difference for the remainder of the runs considered. The wall-to-fluid heat transfer was predicted reasonably well, and the predicted wall superheats were in reasonable agreement with measured data with a maximum relative error of less than 13%. The effects of pressure, test section power, and flow rate on the axial variation of tube wall temperature are predicted reasonably well for a large range of operating parameters. A comparison of the predicted and measured local wall. The thermal-hydraulic model in TRAC/PF1-MOD2 was used to predict the axial variation of void fraction as measured in Winfrith post-CHF tests. The predictions for reflood calculations were reasonable. The model correctly predicted the trends in void fraction as a result of the effect of pressure and power, with the effect of pressure being more apparent than that of power. 13 refs
Sodium-fuel interaction: dropping experiments and subassembly test

International Nuclear Information System (INIS)

Holtbecker, H.; Schins, H.; Jorzik, E.; Klein, K.

1978-01-01

Nine dropping tests, which bring together 2 to 4 kg of molten UO 2 with 150 l sodium, showed the incoherency and non-violence of these thermal interactions. The pressures can be described by sodium incipient boiling and bubble collapse; the UO 2 fragmentation by thermal stress and bubble collapse impact forces. The mildness of the interaction is principally due to the slowness and incoherency of UO 2 fragmentation. This means that parametric models which assume instantaneous mixing and fragmentation are of no use for the interpretation of dropping experiments. One parametric model, the Caldarola Fuel Coolant Interaction Variable Mass model, is being coupled to the two dimensional time dependent hydrodynamic REXCO-H code. In a first step the coupling is applicated to a monodimensional geometry. A subassembly test is proposed to validate the model. In this test rapid mixing between UO 2 and sodium has to be obtained. Dispersed molten UO 2 fuel is obtained by flashing injected sodium drops inside a UO 2 melt. This flashing is theoretically explained and modelled as a superheat limited explosion. The measured sodium drop dwell times of two experiments are compared to results obtained from the mentioned theory, which is the basis of the Press 2 Code
Corrosion investigations at Masnedoe combined heat and power plant. Part VI

Energy Technology Data Exchange (ETDEWEB)

Montgomery, M. [Danmarks Tekniske Univ., Dept. for Manufacturing Engineering, Kgs Lyngby (Denmark); Karlsson, A. [ENERGI E2, Power Company, Copenhagen (Denmark); Hede Larsen, O. [Elsam - Fynsvaerket, Fredericia (Denmark)

2001-02-01

In Denmark, straw and other types of biomass are used for generating energy in power plats. Straw is considered a carbon dioxide neutral fuel and is therefore environmentally acceptable. Masnedoe CHP Plant is a straw-fired power plant on Sjaelland, Denmark. Corrosion tests were undertaken at Masnedoe CHP Plant by building a test superheater loop and subject it to higher steam temperatures than those of the actual plant. In addition a test section welded into superheater was investigated. The conclusions from the project are as follows: 1. The corrosion rates of the steels investigated are very close to one another and differences are small. 2. For the lower steam of 450 deg. C, a parabolic kinetic of oxide growth is not seen but more a paralinear corrosion rate for TP347H and a linear corrosion rate for the 12% Cr steel. 3. At temperatures above approx. 520 deg. C metal temperature for the austenitic steels, grain boundary attack is seen as a precursor for corrosion within the metal grains. For HCM12, attack of individual metal grains is also seen. The corrosion attack leads to depletion of chromium and manganese from the surface of the alloy. It is at these temperatures general corrosion changes to grain boundary corrosion attack. 4. Over one of the test superheater loops, varying corrosion rates could be measured that could not be explained by the change in steam temperature. This was related to the flue gas direction giving a higher surface metal temperature, however, there may be other factors giving localised high heat flux and therefore a higher metal temperature. The corrosion rate was lower this year (1999-2000) than the previous year and this is attributed to the lower flue gas temperatures or other factors such as a change in fuel or combustion characteristics. It must be noted that where the flue gas temperature is assumed to be highest similar corrosion rates are observed for both 1998-1999 and 1999-2000. There is much evidence to indicate that after
Method for controlling a coolant liquid surface of cooling system instruments in an atomic power plant

International Nuclear Information System (INIS)

Monta, Kazuo.

1974-01-01

Object: To prevent coolant inventory within a cooling system loop in an atomic power plant from being varied depending on loads thereby relieving restriction of varied speed of coolant flow rate to lowering of a liquid surface due to short in coolant. Structure: Instruments such as a superheater, an evaporator, and the like, which constitute a cooling system loop in an atomic power plant, have a plurality of free liquid surface of coolant. Portions whose liquid surface is controlled and portions whose liquid surface is varied are adjusted in cross-sectional area so that the sum total of variation in coolant inventory in an instrument such as a superheater provided with an annulus portion in the center thereof and an inner cylindrical portion and a down-comer in the side thereof comes equal to that of variation in coolant inventory in an instrument such as an evaporator similar to the superheater. which is provided with an overflow pipe in its inner cylindrical portion or down-comer, thereby minimizing variation in coolant inventory of the entire coolant due to loads thus minimizing variation in varied speed of the coolant. (Kamimura, M.)
Influence of Test Section Geometry on the Blast Environment in an Explosively Driven Conical Shock Tube

Science.gov (United States)

2018-03-30

ARL-TR-8335•MAR 2018 US Army Research Laboratory Influence of Test Section Geometry on theBlast Environment in an Explosively DrivenConical Shock...ARL-TR-8335•MAR 2018 US Army Research Laboratory Influence of Test Section Geometry on theBlast Environment in an Explosively DrivenConical Shock...TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f
Analysis of the heat and mass transfer processes of a UO2 bubble in sodium for the Fuel Aerosol Simulant Test (FAST)

International Nuclear Information System (INIS)

Tobias, M.L.

1979-01-01

The anticipated behavior of uranium oxide vapor bubbles produced by the capacitor discharge vaporization (CDV) method in the Fuel Aerosol Simulant Test (FAST) Facility is discussed on the basis of relatively simple physical models. Results of calculations for the rate of bubble rise and for heat and mass transfer rates are presented. Parametric studies indicate that future analysis efforts should emphasize the diffusion condensation process and the loss of heat from the bubble by radiation. Transfer of heat in the surrounding sodium is rapid enough that simplified models should be adequate. No important effects were noted in connection with bubble depth, initial quantity of UO 2 , or initial superheat
To test or not to test: A cross-sectional survey of the psychosocial determinants of self-testing for cholesterol, glucose, and HIV

Directory of Open Access Journals (Sweden)

Dinant Geert-Jan

2011-02-01

Full Text Available Abstract Background Although self-tests are increasingly available and widely used, it is not clear whether their use is beneficial to the users, and little is known concerning the determinants of self-test use. The aim of this study was to identify the determinants of self-test use for cholesterol, glucose, and HIV, and to examine whether these are similar across these tests. Self-testing was defined as using in-vitro tests on body materials, initiated by consumers with the aim of diagnosing a particular disorder, condition, or risk factor for disease. Methods A cross-sectional Internet survey was conducted among 513 self-testers and 600 non-testers, assessing possible determinants of self-test use. The structured questionnaire was based on the Health Belief Model, Theory of Planned Behavior, and Protection Motivation Theory. Data were analyzed by means of logistic regression. Results The results revealed that perceived benefits and self-efficacy were significantly associated with self-testing for all three conditions. Other psychosocial determinants, e.g. gender, cues to action, perceived barriers, subjective norm, and moral obligation, seemed to be more test-specific. Conclusions Psychosocial determinants of self-testing are not identical for all tests and therefore information about self-testing needs to be tailored to a specific test. The general public should not only be informed about advantages of self-test use but also about the disadvantages. Designers of information about self-testing should address all aspects related to self-testing to stimulate informed decision making which, in turn, will result in more effective self-test use.

Corrosion Investigations in Straw-Fired Power Plants in Denmark

DEFF Research Database (Denmark)

Montgomery, Melanie; Frandsen, Flemming; Karlsson, A

2001-01-01

of accelerated corrosion. The type of corrosion attack can be directly ascribed to the composition of the deposit and the metal surface temperature. A series of field tests have been undertaken in the various straw-fired power plants in Denmark, namely the Masnedø, Rudkøbing and Ensted CHP plants. Three types......In Denmark, straw and other types of biomass are used for generating energy in power plants. Straw has the advantage that it is a "carbon dioxide neutral fuel" and therefore environmentally acceptable. Straw combustion is associated with corrosion problems which are not encountered in coal-fired...... of exposure were undertaken to investigate corrosion: a) the exposure of metal rings on water/air cooled probes, b) the exposure of test tubes in a test superheater, and c) the exposure of test tubes in existing superheaters. Thus both austenitic steels and ferritic steels were exposed in the steam...
Verification Test for Ultra-Light Deployment Mechanism for Sectioned Deployable Antenna Reflectors

Science.gov (United States)

Zajac, Kai; Schmidt, Tilo; Schiller, Marko; Seifart, Klaus; Schmalbach, Matthias; Scolamiero, Lucio

2013-09-01

The ultra-light deployment mechanism (UDM) is based on three carbon fibre reinforced plastics (CFRP) curved tape springs made of carbon fibre / cyanate ester prepregs.In the frame of the activity its space application suitability for the deployment of solid reflector antenna sections was investigated. A projected diameter of the full reflector of 4 m to 7 m and specific mass in the order of magnitude of 2.6kg/m2 was focused for requirement derivation.Extensive verification tests including health checks, environmental and functional tests were carried out with an engineering model to enable representative characterizing of the UDM unit.This paper presents the design and a technical description of the UDM as well as a summary of achieved development status with respect to test results and possible design improvements.
Structural damping results from vibration tests of straight piping sections

International Nuclear Information System (INIS)

Ware, A.G.; Thinnes, G.L.

1984-01-01

EG and G Idaho is assisting the USNRC and the Pressure Vessel Research Committee in supporting a final position on revised damping values for structural analyses of nuclear piping systems. As part of this program, a series of vibrational tests on 76-mm and 203-mm (3-in. amd 8-in.) Schedule 40 carbon steel piping was conducted to determine the changes in structural damping due to various parametric effects. The 10-m (33-ft) straight sections of piping were rigidly supported at the ends. Spring, rod, and constant force hangers, as well as a sway brace and snubbers were included as intermediate supports. Excitation was provided by low-force level hammer inpacts, a hydraulic shaker, and a 445-kN (50-ton) overhead crane. Data was recorded using acceleration, strain, and displacement time histories. This paper presents results from the testing showing the effect of stress level and type of supports on structural damping in piping
Longitudinal Acceleration Tests of Overhead Luggage Bins and Auxiliary Fuel Tank in a Transport Airplane Airframe Section

National Research Council Canada - National Science Library

McGuire, Robert

1999-01-01

This report contains the description and test results of overhead stowage bin calibrations and longitudinal impact testing of a 10-foot transport airframe section conducted at the Transportation Research Center Inc. (TRC...
Mixed Waste Management Facility (MWMF) closure, Savannah River Plant: Clay cap test section construction report

Energy Technology Data Exchange (ETDEWEB)

1988-02-26

This report contains appendices 3 through 6 for the Clay Cap Test Section Construction Report for the Mixed Waste Management Facility (MWMF) closure at the Savannah River Plant. The Clay Cap Test Program was conducted to evaluate the source, lab. permeability, in-situ permeability, and compaction characteristics, representative of kaolin clays from the Aiken, South Carolina vicinity. (KJD)
An evaluation of corrosion resistant alloys by field corrosion test in Japanese refuse incineration plants

International Nuclear Information System (INIS)

Kawahara, Yuuzou; Nakamura, Masanori; Shibuya, Eiichi; Yukawa, Kenichi

1995-01-01

As the first step for development of the corrosion resistant superheater tube materials of 500 C, 100 ata used in high efficient waste-to-energy plants, field corrosion tests of six conventional alloys were carried out at metal temperatures of 450 C and 550 C for 700 and 3,000 hours in four typical Japanese waste incineration plants. The test results indicate that austenitic alloys containing approximately 80 wt% [Cr+Ni] show excellent corrosion resistance. When the corrosive environment is severe, intergranular corrosion of 40∼200 microm depth occurs in stainless steel and high alloyed materials. It is confirmed quantitatively that corrosion behavior is influenced by environmental corrosion factors such as Cl concentration and thickness of deposits on tube surface, metal temperature, and flue gas temperature. The excellent corrosion resistance of high [Cr+Ni+Mo] alloys such as Alloy 625 is explained by the stability of its protective oxide, such that the time dependence of corrosion nearly obeys the parabolic rate law
Skin Sensitive Difference of Human Body Sections under Clothing-Smirnov Test of Skin Surface Temperatures' Dynamic Changing

Institute of Scientific and Technical Information of China (English)

LI Jun; WU Hai-yan; WANG Yun-yi

2004-01-01

Skin sensitive difference of human body sections under clothing is the theoretic foundation of thermal insulation clothing design.By a new method of researching on clothing comfort perception,the skin temperature live changing procedure of human body sections affected by the same cold stimulation is inspected.Furthermore with the Smirnov test the skin temperatures dynamic changing patterns of main human body sections are obtained.
Round robin test programmes in the reliability of thick section ultrasonic inspections: state of the art report

International Nuclear Information System (INIS)

Watkins, B.

1987-03-01

Inspection reliability is firstly defined and it is shown how difficult it is to be assessed as the influence of such factors as human performance, equipment malfunction and intrinsic technique capability are difficult to quantify. The manufacture of round robin test specimens is then considered: types of flaw, fabrication of test samples. The results of various round robin test programmes that have been carried out to determine both the capability and reliability of NDE to detect and size flaws in steel section for thick sections directly relevant to the requirements of the nuclear industry, are then reviewed and discussed: US Pressure Vessel research committee programme, PISC I Programme, the defect detection trials, and PISC II Programme
Critical Heat Flux Experiments on the Reactor Vessel Wall Using 2-D Slice Test Section

International Nuclear Information System (INIS)

Jeong, Yong Hoon; Chang, Soon Heung; Baek, Won-Pil

2005-01-01

The critical heat flux (CHF) on the reactor vessel outer wall was measured using the two-dimensional slice test section. The radius and the channel area of the test section were 2.5 m and 10 cm x 15 cm, respectively. The flow channel area and the heater width were smaller than those of the ULPU experiments, but the radius was greater than that of the ULPU. The CHF data under the inlet subcooling of 2 to 25 deg. C and the mass flux 0 to 300 kg/m 2 .s had been acquired. The measured CHF value was generally slightly lower than that of the ULPU. The difference possibly comes from the difference of the test section material and the thickness. However, the general trend of CHF according to the mass flux was similar with that of the ULPU. The experimental CHF data were compared with the predicted values by SULTAN correlation. The SULTAN correlation predicted well this study's data only for the mass flux higher than 200 kg/m 2 .s, and for the exit quality lower than 0.05. The local condition-based correlation was developed, and it showed good prediction capability for broad quality (-0.01 to 0.5) and mass flux ( 2 .s) conditions with a root-mean-square error of 2.4%. There were increases in the CHF with trisodium phosphate-added water
Evaluation of mechanical design fire brick at test section on the HeaTiNG-02

International Nuclear Information System (INIS)

Dedy Haryanto; Riswan Djambiar; Sagino; Edy Sumarno

2013-01-01

The activity was carried out due to the modification of the heating in the HeaTiNG-02 test section. Modification of the heater needs to be done to overcome the obstacles that arise as part of the test section is used. Constraint that often arises is the fall of the heating source with super khantal material when it reaches a certain temperature. To mitigate the super khantal position is initially converted into a vertical position horizontal. The change from vertical to horizontal position on super khantal cause any deformities in refractory fire brick which serves as a support super khantal. Manufacture of refractory design fire brick formation and mechanical strength evaluation performed using CATIA V5 R20 software. Evaluation of fireproof rock mechanics to be based on the mechanical properties of alumina as a refractory material of fire brick. The results of the analysis have a fire brick design stress greater than the bend strength alumina materials, so that the necessary checks before and after the experiment as well as the replacement of refractory fire brick if something is broken. Translational greatest displacement 0.453 mm at a temperature of 1575 K did not give any meaningful form. Thus the refractory fire brick design can be used as heating source support in the HeaTiNG-02 test section with checks before and after the operation. (author)
Improving clinical cognitive testing: report of the AAN Behavioral Neurology Section Workgroup.

Science.gov (United States)

Daffner, Kirk R; Gale, Seth A; Barrett, A M; Boeve, Bradley F; Chatterjee, Anjan; Coslett, H Branch; D'Esposito, Mark; Finney, Glen R; Gitelman, Darren R; Hart, John J; Lerner, Alan J; Meador, Kimford J; Pietras, Alison C; Voeller, Kytja S; Kaufer, Daniel I

2015-09-08

To evaluate the evidence basis of single-domain cognitive tests frequently used by behavioral neurologists in an effort to improve the quality of clinical cognitive assessment. Behavioral Neurology Section members of the American Academy of Neurology were surveyed about how they conduct clinical cognitive testing, with a particular focus on the Neurobehavioral Status Exam (NBSE). In contrast to general screening cognitive tests, an NBSE consists of tests of individual cognitive domains (e.g., memory or language) that provide a more comprehensive diagnostic assessment. Workgroups for each of 5 cognitive domains (attention, executive function, memory, language, and spatial cognition) conducted evidence-based reviews of frequently used tests. Reviews focused on suitability for office-based clinical practice, including test administration time, accessibility of normative data, disease populations studied, and availability in the public domain. Demographic and clinical practice data were obtained from 200 respondents who reported using a wide range of cognitive tests. Based on survey data and ancillary information, between 5 and 15 tests in each cognitive domain were reviewed. Within each domain, several tests are highlighted as being well-suited for an NBSE. We identified frequently used single-domain cognitive tests that are suitable for an NBSE to help make informed choices about clinical cognitive assessment. Some frequently used tests have limited normative data or have not been well-studied in common neurologic disorders. Utilizing standardized cognitive tests, particularly those with normative data based on the individual's age and educational level, can enhance the rigor and utility of clinical cognitive assessment. © 2015 American Academy of Neurology.
Thermal response test data of five quadratic cross section precast pile heat exchangers.

Science.gov (United States)

Alberdi-Pagola, Maria

2018-06-01

This data article comprises records from five Thermal Response Tests (TRT) of quadratic cross section pile heat exchangers. Pile heat exchangers, typically referred to as energy piles, consist of traditional foundation piles with embedded heat exchanger pipes. The data presented in this article are related to the research article entitled "Comparing heat flow models for interpretation of precast quadratic pile heat exchanger thermal response tests" (Alberdi-Pagola et al., 2018) [1]. The TRT data consists of measured inlet and outlet temperatures, fluid flow and injected heat rate recorded every 10 min. The field dataset is made available to enable model verification studies.
A new laser reflectance system capable of measuring changing cross-sectional area of soft tissues during tensile testing.

Science.gov (United States)

Pokhai, Gabriel G; Oliver, Michele L; Gordon, Karen D

2009-09-01

Determination of the biomechanical properties of soft tissues such as tendons and ligaments is dependent on the accurate measurement of their cross-sectional area (CSA). Measurement methods, which involve contact with the specimen, are problematic because soft tissues are easily deformed. Noncontact measurement methods are preferable in this regard, but may experience difficulty in dealing with the complex cross-sectional shapes and glistening surfaces seen in soft tissues. Additionally, existing CSA measurement systems are separated from the materials testing machine, resulting in the inability to measure CSA during testing. Furthermore, CSA measurements are usually made in a different orientation, and with a different preload, prior to testing. To overcome these problems, a noncontact laser reflectance system (LRS) was developed. Designed to fit in an Instron 8872 servohydraulic test machine, the system measures CSA by orbiting a laser transducer in a circular path around a soft tissue specimen held by tissue clamps. CSA measurements can be conducted before and during tensile testing. The system was validated using machined metallic specimens of various shapes and sizes, as well as different sizes of bovine tendons. The metallic specimens could be measured to within 4% accuracy, and the tendons to within an average error of 4.3%. Statistical analyses showed no significant differences between the measurements of the LRS and those of the casting method, an established measurement technique. The LRS was successfully used to measure the changing CSA of bovine tendons during uniaxial tensile testing. The LRS developed in this work represents a simple, quick, and accurate way of reconstructing complex cross-sectional profiles and calculating cross-sectional areas. In addition, the LRS represents the first system capable of automatically measuring changing CSA of soft tissues during tensile testing, facilitating the calculation of more accurate biomechanical properties.
Mathematics simulation and experiments of continuous casting with strip feeding in mold

Directory of Open Access Journals (Sweden)

M. G. Shen

2017-01-01

Full Text Available Steel strip feeding technology can reduce the degree of superheat of the molten steel, change the solidification order of the molten steel; raise the equiaxed crystal rate of the slab and improve the continuous casting quality. The paper establishes the mathematical model of heat transfer and temperature field of casting billet of steel strip feeding in continuous casting mold. Results show that if Plate Billet is 1 000 mm × 220 mm and the steel strip is 100 mm × 3 mm, feeding position of parallel is 250 mm from the narrow side. When the feeding speed is 3,6 m/min, the superheat degree can be reduced by 5 °C, and the solidification length can be reduced by 2,9 m. When the feeding speed is 6 m/min, the superheat degree can be reduced by about 9 °C, and the solidification length can be reduced by 3,7 m. The results of the test in a steel plant are in good agreement with the experimental results.
Review Report on the Design of In-Pile Test Section(IPS)

International Nuclear Information System (INIS)

Lee, Jong Min; Park, Kook Nam; Shim, Bong Sik; Lee, Chung Young; Chi, Dae Young; Park, Su Ki; Ahn, Sung Ho; Kim, Young Ki; Lee, Kye Hong; Kim, Kwan Hyun

2009-01-01

The In-Pile Test Section(IPS) accommodating fuel pins has loaded IR-1 hole in HANARO has double pressure vessel for the design conditions of 350 deg. C, 17.5 MPa and is composed of outer assembly and inner assembly. Dummy fuel, dummy fuel supports and Top flange are the main components in inner assembly and inner pressure vessel, outer pressure vessel and head are the components in outer assembly. The IPS at current status has dummy fuels and confirm the requirements for the IPS design improvements during the design, manufacturing and installation process. Head, Top Flange, Instrumentation Feed through, Lifting Eye, Fuel Carrier Leg, Retainer and Nozzle cover are the main parts that the design needs to be changed. This report suggest the needs for the IPS design modification and it would be reflected to the new IPS design which would accommodating test fuel pins
Review Report on the Design of In-Pile Test Section(IPS)

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Min; Park, Kook Nam; Shim, Bong Sik; Lee, Chung Young; Chi, Dae Young; Park, Su Ki; Ahn, Sung Ho; Kim, Young Ki; Lee, Kye Hong; Kim, Kwan Hyun

2009-01-15

The In-Pile Test Section(IPS) accommodating fuel pins has loaded IR-1 hole in HANARO has double pressure vessel for the design conditions of 350 deg. C, 17.5 MPa and is composed of outer assembly and inner assembly. Dummy fuel, dummy fuel supports and Top flange are the main components in inner assembly and inner pressure vessel, outer pressure vessel and head are the components in outer assembly. The IPS at current status has dummy fuels and confirm the requirements for the IPS design improvements during the design, manufacturing and installation process. Head, Top Flange, Instrumentation Feed through, Lifting Eye, Fuel Carrier Leg, Retainer and Nozzle cover are the main parts that the design needs to be changed. This report suggest the needs for the IPS design modification and it would be reflected to the new IPS design which would accommodating test fuel pins.
Accelerated load testing of geosynthetic base reinforced pavement test sections.

Science.gov (United States)

2011-02-01

The main objective of this research is to evaluate the benefits of geosynthetic stabilization and reinforcement of subgrade/base aggregate layers in flexible pavements built on weak subgrades and the effect of pre-rut pavement sections, prior to the ...
Test of virtual photon theory. [Cross sections, square-well potential, 0 to 300 MeV

Energy Technology Data Exchange (ETDEWEB)

Dressler, E T; Tomusiak, E L [Saskatchewan Univ., Saskatoon (Canada). Saskatchewan Accelerator Lab.

1976-11-30

In order to extract a photodisintegration cross section in the c.m. system from an electrodisintegration cross section measured in the lab system, one has to assume that the electrons are mostly scattered forward and that the monopole contributions are negligible. To test the validity of these approximations, a square well potential was assumed for the initial and final states and the photodisintegration cross section was calculated exactly within this model. These results were then compared with the results one would obtain using the virtual photon theory approximations for electron energies of 0-300 MeV and excitation energies up to 40 MeV. In comparing the two results, it is shown how and why the virtual photon theory approximations fail in certain kinematical regions.
A study of the effect of binary oxide materials in a single droplet vapor explosion

Energy Technology Data Exchange (ETDEWEB)

Hansson, R.C., E-mail: rch@kth.se [Royal Institute of Technology, Stockholm (Sweden); Dinh, T.N.; Manickam, L.T. [Royal Institute of Technology, Stockholm (Sweden)

2013-11-15

In an effort to explore fundamental mechanisms that may govern the effect of melt material on vapor explosion's triggering, fine fragmentation and energetics, a series of experiments using a binary-oxide mixture with eutectic and non-eutectic compositions were performed. Interactions of a hot liquid (WO{sub 3}–CaO) droplet and a volatile liquid (water) were investigated in well-controlled, externally triggered, single-droplet experiments conducted in the Micro-interactions in steam explosion experiments (MISTEE) facility. The tests were visualized by means of a synchronized digital cinematography and continuous X-ray radiography system, called simultaneous high-speed acquisition of X-ray radiography and photography (SHARP). The acquired images followed by further analysis indicate milder interactions for the droplet with non-eutectic melt composition in the tests with low melt superheat, whereas no evident differences between eutectic and non-eutectic melt compositions regarding bubble dynamics, energetics and melt preconditioning was observed in the tests with higher melt superheat.
A study of the effect of binary oxide materials in a single droplet vapor explosion

International Nuclear Information System (INIS)

Hansson, R.C.; Dinh, T.N.; Manickam, L.T.

2013-01-01

In an effort to explore fundamental mechanisms that may govern the effect of melt material on vapor explosion's triggering, fine fragmentation and energetics, a series of experiments using a binary-oxide mixture with eutectic and non-eutectic compositions were performed. Interactions of a hot liquid (WO 3 –CaO) droplet and a volatile liquid (water) were investigated in well-controlled, externally triggered, single-droplet experiments conducted in the Micro-interactions in steam explosion experiments (MISTEE) facility. The tests were visualized by means of a synchronized digital cinematography and continuous X-ray radiography system, called simultaneous high-speed acquisition of X-ray radiography and photography (SHARP). The acquired images followed by further analysis indicate milder interactions for the droplet with non-eutectic melt composition in the tests with low melt superheat, whereas no evident differences between eutectic and non-eutectic melt compositions regarding bubble dynamics, energetics and melt preconditioning was observed in the tests with higher melt superheat

Four stream breakup of molten IFR [Integral Fast Reactor] metal fuel in sodium

International Nuclear Information System (INIS)

Gabor, J.D.; Purviance, R.T.; Aeschlimann, R.W.; Spencer, B.W.

1988-01-01

Tests have been conducted in which the breakup behavior of kilogram quantities of molten uranium, uranium-zirconium alloy, and uranium-iron alloy pour streams in 600C sodium was studied. A sodium depth of less than 0.3 m was required for hydrodynamic breakup and freezing of 25-mm pour streams of uranium and uranium-zirconium alloy with up to 400C melt superheat. The breakup material was primarily in the form of filaments and sheets with a settled bed voidage on the order of 0.9. The uranium-iron alloy with 800C melt superheat exhibited similar behavior except a sodium depth somewhat greater than 0.3 m was required for breakup and freezing of the particles
Numerical analyses of flashing jet structure and droplet size characteristics

International Nuclear Information System (INIS)

Duan Riqiang; Jiang Shengyao; Koshizuka, Seiichi; Oka, Yoshiaki; Yamaguchi, Akira; Takata, Takashi

2006-01-01

In this paper, flashing jets are numerically simulated using the MPS method. The boiling mode for flashing is identified as surface boiling mode, based on the postulation of jets from a short nozzle under high depressurization. The Homogeneous Non-equilibrium Relaxation Model (HRM) is used for calculating the evaporation rate of flashing. The numerical simulation results show that flashing jets comprise an inner intact core which is surrounded by two-phase droplet flow. The effect of degree of superheat on the jet topological geometry is investigated. With increasing degree of superheat, the topological shape of flashing jets evolves from cylindrical core for low degree of superheat to cone-shaped core for high degree of superheat, and meanwhile the extinction length comes to decrease and tends asymptotically constant as the injection temperature approaches the saturation temperature corresponding to the injection pressure. The analyses of the droplet size distribution engendered from primary breakup of flashing jets show that: two peaks exist for droplet size distribution at lower degree of superheat; however, merely one peak for higher degree of superheat. From droplet size distribution, it is revealed that the primary breakup mechanism of flashing jets can be attributed to dominant mechanical breakup mode plus enhancement via surface evaporation. (author)
77 FR 28281 - Withdrawal of Revocation of TSCA Section 4 Testing Requirements for One High Production Volume...

Science.gov (United States)

2012-05-14

... Withdrawal of Revocation of TSCA Section 4 Testing Requirements for One High Production Volume Chemical...]amino]- (CAS No. 1324-76-1), also known as C.I. Pigment Blue 61. EPA received an adverse comment regarding C.I. Pigment Blue 61. This document withdraws the revocation of testing requirements for C.I...
Testing of the IRDF-90 cross-section library in benchmark neutron spectra

International Nuclear Information System (INIS)

Nolthenius, H.J.; Zsolnay, E.M.; Szondi, E.J.

1993-09-01

The new version of the International Reactor Dosimetry File IRDF-90 (called ''Version April 1993'') has been tested by calculation of average cross-sections and their uncertainties in a coarse three energy group structure and by neutron spectrum adjustments in reference neutron spectra. This paper presents the results obtained and compares them with the corresponding ones of the old IRDF-85 and with the data of the Nuclear Data Guide for Reactor Neutron Metrology. The applicability of the new library in the field of neutron metrology is discussed. (orig.)
Longitudinal Acceleration Test of Overhead Luggage Bins and Auxiliary Fuel Tank in a Transport Airplane Airframe Section, Part 2

National Research Council Canada - National Science Library

McGuire, Robert

2000-01-01

This report contains the description and test results of overhead stowage bin calibrations and longitudinal impact testing of a 10-foot transport airframe section conducted at the Transportation Research Center Inc. (TRC...
Construction of a 2- by 2-foot transonic adaptive-wall test section at the NASA Ames Research Center

Science.gov (United States)

Morgan, Daniel G.; Lee, George

1986-01-01

The development of a new production-size, two-dimensional, adaptive-wall test section with ventilated walls at the NASA Ames Research Center is described. The new facility incorporates rapid closed-loop operation, computer/sensor integration, and on-line interference assessment and wall corrections. Air flow through the test section is controlled by a series of plenum compartments and three-way slide vales. A fast-scan laser velocimeter was built to measure velocity boundary conditions for the interference assessment scheme. A 15.2-cm- (6.0-in.-) chord NACA 0012 airfoil model will be used in the first experiments during calibration of the facility.
BUGLE-93 (ENDF/B-VI) cross-section library data testing using shielding benchmarks

International Nuclear Information System (INIS)

Hunter, H.T.; Slater, C.O.; White, J.E.

1994-01-01

Several integral shielding benchmarks were selected to perform data testing for new multigroup cross-section libraries compiled from the ENDF/B-VI data for light water reactor (LWR) shielding and dosimetry. The new multigroup libraries, BUGLE-93 and VITAMIN-B6, were studied to establish their reliability and response to the benchmark measurements by use of radiation transport codes, ANISN and DORT. Also, direct comparisons of BUGLE-93 and VITAMIN-B6 to BUGLE-80 (ENDF/B-IV) and VITAMIN-E (ENDF/B-V) were performed. Some benchmarks involved the nuclides used in LWR shielding and dosimetry applications, and some were sensitive specific nuclear data, i.e. iron due to its dominant use in nuclear reactor systems and complex set of cross-section resonances. Five shielding benchmarks (four experimental and one calculational) are described and results are presented
How do people respond to self-test results? A cross-sectional survey

Directory of Open Access Journals (Sweden)

de Vries Nanne K

2010-10-01

Full Text Available Abstract Background Self-tests, tests on medical conditions that can be performed by consumers without consulting a doctor first, are frequently used. Nevertheless, there are concerns about the safety of self-testing, as it may delay diagnosis and appropriate treatment in the case of inappropriate use of the test, or false-negative results. It is unclear whether self-tests stimulate appropriate follow-up behaviour. Our aim was to examine the frequency of self-test use, consumers' response to self-test results in terms of their confidence in the result, reassurance by the test result, and follow-up behaviour. Methods A two step cross-sectional survey was designed. A random sample of 6700 Internet users in an existing Internet panel received an online questionnaire on the use of self-tests. Self-tests were defined as tests on body materials, initiated by consumers with the aim to diagnose a disease or risk factor. A second questionnaire on consumers' response to self-test results was sent to the respondents that were identified as a self-tester in the first questionnaire (n = 703. Results 18.1% (799/4416 of the respondents had ever performed a self-test, the most frequently used tests being those for diabetes (5.3%, kidney disease (4.9%, cholesterol (4.5%, urinary tract infection (1.9% and HIV/AIDS and Chlamydia (both 1.6%. A total of 78.1% of the testers with a normal test result and 81.4% of those with an abnormal result reported confidence in this result. Almost all (95.6% of the testers with a normal result felt reassured. After a normal result, 78.1% did not take any further action and 5.8% consulted a doctor. The corresponding figures after an abnormal test result were 9.3% and 72.2%, respectively. Conclusions Respondents who had performed a self-test seemed to base their follow-up behaviour on the result of the test. They had confidence in the test result, and were often reassured by a normal result. After an abnormal result, most self
The relationship between Test Takers’ Multiple Intelligences and Their Performance on the Reading Sections of TOEFL and IELTS

Directory of Open Access Journals (Sweden)

Minoo Alemi

2010-04-01

Full Text Available The present study aimed at investigating the hypothetical relationship between the multiple intelligences of test takers and their performance on the reading sections of TOEFL and IELTS. Howard Gardner’s theory of multiple intelligences suggests that intelligence is not a single and solely inborn capacity, rather a multiple construct which is only partly genetic, and can be crystallized or paralyzed over one’s lifetime. Based on the theory, there are eight types of intelligence: linguistic, mathematical, musical, bodily, spatial, intrapersonal, interpersonal and naturalist, but the list is not exhaustive. The multiple intelligences of test takers were estimated by means of MIDAS, the Multiple Intelligences Developmental Assessment Scales, developed by Shearer (1994. Subsequently, the bias detection for the reading section of TOEFL was carried out on 90 participants, and this subtest was found to correlate positively with linguistic and logical intelligences. By the same token, 89 out of the 163 participants in the study were included in the analysis of the relationship between the multiple intelligences of test takers and their performance on the reading section of IELTS, and this test proved biased toward linguistic and spatial intelligences. The implications concern the inadequacy of the definition of language proficiency .Moreover, Measurement-Driven Instruction courses and preparatory materials of the two proficiency tests, TOEFL and IELTS, can benefit from the results of the study by being designed in such a way as to represent the intelligences which are positively correlated with performance on the tests in question.
IR1 flow tube and In-Pile Test Section Pressure drop test for the 3-Pin Fuel Test Loop

Energy Technology Data Exchange (ETDEWEB)

Lee, H. H.; Park, K. N.; Chi, D. Y.; Sim, B. S.; Park, S. K.; Lee, J. M.; Lee, C. Y.; Kim, H. N

2006-02-15

The in-pile Section (IPS) of 3-pin Fuel Test Loop(FTL) shall be installed in the vertical hole call IR1 of HANARO reactor core. In order to verify the pressure drop and flow rate both the inside region of IPS at the annular region between IPS and IR1 flow tube, a pressure drop was measured by varing the flow rate on both regions. The measured pressure drop in the annular region is 209kpa at 14.9kg/s which meets the limiting condition of operation of 200kpa. The measured pressure drop in side the IPS becomes 260.25kpa which is lower than the designed value of 306.65kpa. As the pressure drop is lower than the design value, it is quite conservative from the safety and operating point of view.
Feasibility of supervised self-testing using an oral fluid-based HIV rapid testing method: a cross-sectional, mixed method study among pregnant women in rural India

OpenAIRE

Sarkar, Archana; Mburu, Gitau; Shivkumar, Poonam Varma; Sharma, Pankhuri; Campbell, Fiona; Behera, Jagannath; Dargan, Ritu; Mishra, Surendra Kumar; Mehra, Sunil

2016-01-01

Introduction: HIV self-testing can increase coverage of essential HIV services. This study aimed to establish the acceptability, concordance and feasibility of supervised HIV self-testing among pregnant women in rural India. Methods: A cross-sectional, mixed methods study was conducted among 202 consenting pregnant women in a rural Indian hospital between August 2014 and January 2015. Participants were provided with instructions on how to self-test using OraQuick® HIV antibody test, and subse...
The effect of binary oxide materials on a single droplet vapor explosion triggering

International Nuclear Information System (INIS)

Hansson, R.C.; Manickam, L.T.; Dinh, T.N.

2011-01-01

In order to explore the fundamental mechanism dictated by the material influence on triggering, fine fragmentation and subsequent vapor explosion energetics, a series of experiments using a mixture of eutectic and non-eutectic binary oxide were initiated. Dynamics of the hot liquid (WO 3 -CaO) droplet and the volatile liquid (water) were investigated in the MISTEE (Micro-Interactions in Steam Explosion Experiments) facility by performing well-controlled, externally triggered, single-droplet experiments, using a high-speed visualization system with synchronized digital cinematography and continuous X-ray radiography, called SHARP (Simultaneous High-speed Acquisition of X-ray Radiography and Photography). The acquired images followed by further analysis showed a milder interaction for the non-eutectic melt composition for the tests with low melt superheat, whether no evident differences between eutectic and non-eutectic melt compositions regarding bubble dynamics, energetics and melt preconditioning was perceived for the high melt superheat tests. (author)
Preliminary experiences with material testing at the oxyfuel pilot plant at Schwarze Pumpe

Energy Technology Data Exchange (ETDEWEB)

Hjoernhede, Anders [Vattenfall Power, Gothenborg (Sweden); Montgomery, Melanie [Technical Univ. Denmark, Lyngby (Denmark). Inst. for Mekanisk Teknologi; Vattenfall Heat Nordic, Lyngby (Denmark); Bjurman, Martin; Henderson, Pamela [Vattenfall AB (Sweden). Research and Development; Gerhardt, Alexander [Vattenfall AB, Berlin (Germany). Research and Development

2010-07-01

Several material related issues may arise from oxyfuel combustion of coal due to the presence of CO{sub 2} but also as an effect of the partial recirculation of the flue gas. Two examples are increased corrosion and carburisation which may limit steam data, hence limiting the efficiency. A number of corrosion tests, in both conventional air-firing and oxyfuel mode, have been made in Vattenfalls 30 MW oxyfuel pilot plant located in Schwarze Pumpe, Germany. Internally cooled corrosion probes, equipped with ferritic, austenitic, super austenitic steels as well as Ni-based and FeCrAl alloys, simulating superheaters, economisers and air preheaters were exposed for up to 1500 hrs. The analyses show an indication of higher material wastage in oxyfuel compared to air combustion especially at the lower exposure temperatures. This may be due to increased sulphur concentration in corrosion front, increased heat flux, carburisation or other precipitate formations on austenitic steels and Ni-based alloys. (orig.)
Measurement of single-top cross section and test of anomalous $Wtb$ coupling

Energy Technology Data Exchange (ETDEWEB)

Jung, Ji-Eun [Seoul National Univ. (Korea, Republic of)

2010-01-01

The top quark is most often produced in tt pairs via the strong interaction, however electroweak production of a singly-produced top quark is also possible. Electroweak single-top production is more difficult to observe than tt production. Studying single-top production is important for the following reasons. It provides direct measurement of the CKM matrix element and also single-top events are a background to several searches for SM or non-SM signals, such as Higgs boson searches. The information of spin polarization of top-quark can be used to t est anomalous W-t-b coupling. This thesis describes the result of a measurement of single-top cross-section and a test of anomalous W-t-b coupling using 4.8 f b^-1 of data collected by the CDF Run II experiment at the Fermilab Tevatron. The measured cross-section is 1.83$+0.7\\atop{-0.6}$ pb and measured limit of |Vtb| is 0.41 at 95% CL. The fraction of V+A coupling is 0 ± 28 (%).
Subcooled boiling heat transfer and dryout on a constant temperature microheater

International Nuclear Information System (INIS)

Chen Tailian; Klausner, James F.; Chung, Jacob N.

2004-01-01

An experimental study of single-bubble subcooled boiling heat transfer (ΔT sub =31.5 K) on a small heater with constant wall temperature has been performed to better understand the boiling heat transfer associated with this unique configuration. The heater of 0.27 mm x 0.27 mm is set at different superheats to generate vapor bubbles on the microheater surface. For each superheat, the heater temperature is maintained constant by an electronic feedback control circuit while its power dissipation is measured at a frequency of 4.5 kHz. The single-bubble boiling is characterized by a transient bubble nucleation-departure period and a slow growth period. For the superheat range of 34-114 K in this study, at wall superheats below 84 K, the heater remains partially wetted following bubble departure and subsequent nucleation, and this period is characterized by a heat flux spike. At wall superheats above 90 K, the heater is blanketed with vapor following bubble departure and the heat flux experiences a dip during this period. At all superheats, the slow growth period is characterized by an almost uniform heat flux, and it has been observed that the heater surface is mostly covered by vapor. The unique heat transfer processes associated with boiling on this microheater are considerably different than those typically observed during boiling on a large heater
Cap Bubble Drift Velocity in a Confined Test Section

International Nuclear Information System (INIS)

Xiaodong Sun; Seungjin Kim; Mamoru Ishii; Lincoln, Frank W.; Beus, Stephen G.

2002-01-01

In the two-group interfacial area transport equation, bubbles are categorized into two groups, i.e., spherical/distorted bubbles as group 1 and cap/slug/churn-turbulent bubbles as group 2. The bubble rise velocities for both groups of bubbles may be estimated by the drift flux model by applying different distribution parameters and drift velocities for both groups. However, the drift velocity for group 2 bubbles is not always applicable (when the wall effect becomes important) as in the current test loop of interest where the flow channel is confined by two parallel flat walls, with a dimension of 200-mm in width and 10-mm in gap. The previous experiments indicated that no stable slug flow existed in this test section, which was designed to permit visualization of the flow patterns and bubble characteristics without the distortion associated with curved surfaces. In fact, distorted cap bubbly and churn-turbulent flow was observed. Therefore, it is essential to developed a correlation for cap bubble drift velocity in this confined flow channel. Since the rise velocity of a cap bubble depends on its size, a high-speed movie camera is used to capture images of cap bubbles to obtain the bubble size information. Meanwhile, the rise velocity of cap and elongated bubbles (called cap bubbles hereafter) is investigated by examining the captured images frame by frame. As a result, the conventional correlation of drift velocity for slug bubbles is modified and acceptable agreements between the measurements and correlation estimation are achieved
Testing of cross section libraries for TRIGA criticality benchmark

International Nuclear Information System (INIS)

Snoj, L.; Trkov, A.; Ravnik, M.

2007-01-01

Influence of various up-to-date cross section libraries on the multiplication factor of TRIGA benchmark as well as the influence of fuel composition on the multiplication factor of the system composed of various types of TRIGA fuel elements was investigated. It was observed that keff calculated by using the ENDF/B VII cross section library is systematically higher than using the ENDF/B-VI cross section library. The main contributions (∼ 2 20 pcm) are from 235 U and Zr. (author)
HIV testing and tolerance to gender based violence: a cross-sectional study in Zambia.

Directory of Open Access Journals (Sweden)

Sara Gari

Full Text Available This paper explores the effect of social relations and gender-based conflicts on the uptake of HIV testing in the South and Central provinces of Zambia. We conducted a community-based cross-sectional study of 1716 randomly selected individuals. Associations were examined using mixed-effect multivariable logistic regression. A total of 264 men (64% and 268 women (56% had never tested for HIV. The strongest determinants for not being tested were disruptive couple relationships (OR = 2.48 95% CI = 1.00-6.19; tolerance to gender-based violence (OR = 2.10 95% CI = 1.05-4.32 and fear of social rejection (OR = 1.48 95% CI = 1.23-1.80. In the Zambian context, unequal power relationships within the couple and the community seem to play a pivotal role in the decision to test which until now have been largely underestimated. Policies, programs and interventions to rapidly increase HIV testing need to urgently address gender-power inequity in relationships and prevent gender-based violence to reduce the negative impact on the lives of couples and families.
Forced convection and subcooled flow boiling heat transfer in asymmetrically heated ducts of T-section

International Nuclear Information System (INIS)

Abou-Ziyan, Hosny Z.

2004-01-01

This paper presents the results of an experimental investigation of heat transfer from the heated bottom side of tee cross-section ducts to an internally flowing fluid. The idea of this work is derived from the cooling of critical areas in the cylinder heads of internal combustion engines. Fully developed single phase forced convection and subcooled flow boiling heat transfer data are reported. Six T-ducts of different width and height aspect ratios are tested with distilled water at velocities of 1, 2 and 3 m/s for bulk temperatures of 60 and 80 deg. C, while the heat flux was varied from about 80 to 700 kW/m 2 . The achieved data cover Reynolds numbers in the range of 5.22 x 10 4 to 2.36 x 10 5 , Prandtl numbers in the range from 2.2 to 3.0, duct width aspect ratio between 2.19 and 3.13 and duct height aspect ratio from 0.69 to 2.0. The results revealed that the increase in either the width or height aspect ratio of the T-ducts enhances the convection heat transfer coefficients and the boiling heat fluxes considerably. The following comparisons are provided for coolant velocity of 2 m/s, bulk temperature of 60 deg. C, wall superheat of 20 K and wall to bulk temperature difference of 20 K. As the width aspect ratio increases by 43%, the convection heat transfer coefficient and the boiling heat flux increase by 27% and 39%, respectively. An increase in the height aspect ratio by 290% enhances the convection heat transfer coefficient and the boiling heat fluxes by 82% and 103%, respectively. When the coolant velocity changes from 1 to 2 m/s, the heat transfer coefficient increases by 60% and the boiling heat flux rises by 62-98% for the various tested ducts. The convection heat transfer coefficient increases by 12% and the boiling heat flux decreases by 31% as the bulk fluid temperature rises from 60 to 80 deg. C. A correlation was developed for Nusselt number as a function of Reynolds number, Prandtl number, viscosity ratio and some aspect ratios of the T-duct
Fracture toughness testing of core from the Cambro-Ordovician Section on the Oak Ridge Reservation

International Nuclear Information System (INIS)

Lemiszki, P.J.; Landes, J.D.

1996-01-01

The modified ring test was used to determine the mode I fracture toughness of bedrock cores from the DOE Oak Ridge Reservation in east Tennessee. Low porosity sandstones, limestones, and dolostones from the lower part of the Paleozoic section in Copper Creek and Whiteoak Mountain thrust sheets were sampled. In general, the average mode I fracture toughness decreases from sandstone, dolostone, and limestone. The fracture toughness of the limestones varies between rock units, which is related to different sedimentologic characteristics. Quality of results was evaluated by testing cores of Berea Sandstone and Indiana Limestone, which produced results similar to published results

Research and field tests of staged fracturing technology for casing deformation sections in horizontal shale gas wells

Directory of Open Access Journals (Sweden)

Shimeng Liao

2018-02-01

Full Text Available Horizontal shale gas well fracturing is mostly carried out by pumping bridge plugs. In the case of casing deformation, the bridge plug can not be pumped down to the designated position, so the hole sections below the deformation could not be stimulated according to the design program. About 30% of horizontal shale gas wells in the Changning and Weiyuan Blocks, Sichuan Basin, suffer various casing deformation after fracturing. Previously, the hole sections which could not be stimulated due to casing deformation were generally abandoned. As a result, the resources controlled by shale gas wells weren't exploited effectively and the fracturing effect was impacted greatly. There are a lot of difficulties in investigating casing deformation, such as complex mechanisms, various influencing factors and unpredictable deformation time. Therefore, it is especially important to seek a staged fracturing technology suitable for the casing deformation sections. In this paper, the staged fracturing technology with sand plugs inside fractures and the staged fracturing technology with temporary plugging balls were tested in casing deformation wells. The staged fracturing technology with sand plugs inside fractures was carried out in the mode of single-stage perforation and single-stage fracturing. The staged fracturing technology with temporary plugging balls was conducted in the mode of single perforation, continuous fracturing and staged ball dropping. Then, two kinds of technologies were compared in terms of their advantages and disadvantages. Finally, they were tested on site. According to the pressure response, the pressure monitoring of the adjacent wells and the microseismic monitoring in the process of actual fracturing, both technologies are effective in the stimulation of the casing deformation sections, realizing well control reserves efficiently and guaranteeing fracturing effects. Keywords: Shale gas, Horizontal well, Casing deformation, Staged
Damping test results for straight sections of 3-inch and 8-inch unpressurized pipes

International Nuclear Information System (INIS)

Ware, A.G.; Thinnes, G.L.

1984-04-01

EG and G Idaho is assisting the Nuclear Regulatory Commission and the Pressure Vessel Research Committee in supporting a final position on revised damping values for structural analyses of nuclear piping systems. As part of this program, a series of vibrational tests on unpressurized 3-in. and 8-in. Schedule 40 carbon steel piping was conducted to determine the changes in structural damping due to various parametric effects. The 33-ft straight sections of piping were supported at the ends. Additionally, intermediate supports comprising spring, rod, and constant-force hangers, as well as a sway brace and snubbers, were used. Excitation was provided by low-force-level hammer impacts, a hydraulic shaker, and a 50-ton overhead crane for snapback testing. Data was recorded using acceleration, strain, and displacement time histories. This report presents test results showing the effect of stress level and type of supports on structural damping in piping
Failure evaluation on a high-strength alloy SA213-T91 super heater tube of a power generation

Energy Technology Data Exchange (ETDEWEB)

Ahmad, J.; Purbolaksono, J.; Beng, L.C.; Ahmad, A. [University of Tenaga Nas, Kajang (Malaysia). Dept. of Mechanical Engineering

2010-07-01

This article presents failure investigation on a high-strength alloy SA213-T91 superheater tube. This failure is the first occurrence involving the material in Kapar Power Station Malaysia. The investigation includes visual inspections, hardness measurements, and microscopic examinations. The failed super-heater tube shows a wide open rupture with thin and blunt edges. Hardness readings on all the as-received tubes are used for estimating the operating metal temperature of the super-heater tubes. Microstructures of the failed tube show numerous creep cavities consisting of individual pores and chain of pores which form micro-and macro-cracks. The findings confirmed that the super-heater tube is failed by short-term overheating. Higher temperatures of the flue gas due to the inconsistent feeding of pulverized fuels into the burner is identified to cause overheating of the failed tube.
Approximating a free-field blast environment in the test section of an explosively driven conical shock tube

Science.gov (United States)

Stewart, J. B.

2018-02-01

This paper presents experimental data on incident overpressures and the corresponding impulses obtained in the test section of an explosively driven 10° (full angle) conical shock tube. Due to the shock tube's steel walls approximating the boundary conditions seen by a spherical sector cut out of a detonating sphere of energetic material, a 5.3-g pentolite shock tube driver charge produces peak overpressures corresponding to a free-field detonation from an 816-g sphere of pentolite. The four test section geometries investigated in this paper (open air, cylindrical, 10° inscribed square frustum, and 10° circumscribed square frustum) provide a variety of different time histories for the incident overpressures and impulses, with a circumscribed square frustum yielding the best approximation of the estimated blast environment that would have been produced by a free-field detonation.
Functional performance of the helical coil steam generator, Consolidated Nuclear Steam Generator (CNSG) IV system. Executive summary report

International Nuclear Information System (INIS)

Watson, G.B.

1975-10-01

The objective of this project was to study the functional performance of the CNSG - IV helical steam generator to demonstrate that the generator meets steady-state and transient thermal-hydraulic performance specifications and that secondary flow instability will not be a problem. Economic success of the CNSG concepts depends to a great extent on minimizing the size of the steam generator and the reactor vessel for ship installation. Also, for marine application the system must meet stringent specifications for operating stability, transient response, and control. The full-size two-tube experimental unit differed from the CNSG only in the number of tubes and the mode of primary flow. In general, the functional performance test demonstrated that the helical steam generator concept will exceed the specified superheat of 35F at 100% load. The experimental measured superheat at comparable operating conditions was 95F. Testing also revealed that available computer codes accurately predict trends and overall performance characteristics
The effect of binary oxide materials on a single droplet vapor explosion triggering

Energy Technology Data Exchange (ETDEWEB)

Hansson, R.C.; Manickam, L.T.; Dinh, T.N. [Royal Inst. of Tech., Stockholm (Sweden)

2011-07-01

In order to explore the fundamental mechanism dictated by the material influence on triggering, fine fragmentation and subsequent vapor explosion energetics, a series of experiments using a mixture of eutectic and non-eutectic binary oxide were initiated. Dynamics of the hot liquid (WO{sub 3}-CaO) droplet and the volatile liquid (water) were investigated in the MISTEE (Micro-Interactions in Steam Explosion Experiments) facility by performing well-controlled, externally triggered, single-droplet experiments, using a high-speed visualization system with synchronized digital cinematography and continuous X-ray radiography, called SHARP (Simultaneous High-speed Acquisition of X-ray Radiography and Photography). The acquired images followed by further analysis showed a milder interaction for the non-eutectic melt composition for the tests with low melt superheat, whether no evident differences between eutectic and non-eutectic melt compositions regarding bubble dynamics, energetics and melt preconditioning was perceived for the high melt superheat tests. (author)
Creep-Rupture Behavior of Ni-Based Alloy Tube Bends for A-USC Boilers

Science.gov (United States)

Shingledecker, John

Advanced ultrasupercritical (A-USC) boiler designs will require the use of nickel-based alloys for superheaters and reheaters and thus tube bending will be required. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section II PG-19 limits the amount of cold-strain for boiler tube bends for austenitic materials. In this summary and analysis of research conducted to date, a number of candidate nickel-based A-USC alloys were evaluated. These alloys include alloy 230, alloy 617, and Inconel 740/740H. Uniaxial creep and novel structural tests and corresponding post-test analysis, which included physical measurements, simplified analytical analysis, and detailed microscopy, showed that different damage mechanisms may operate based on test conditions, alloy, and cold-strain levels. Overall, creep strength and ductility were reduced in all the alloys, but the degree of degradation varied substantially. The results support the current cold-strain limits now incorporated in ASME for these alloys for long-term A-USC boiler service.
Interation between a superheated uranium dioxide jet and cold concrete

International Nuclear Information System (INIS)

Howe, L.D.; Denham, M.K.; Turland, B.D.; Dop, L.M.G.; Humphreys, R.J.

1992-01-01

A scoping experiment has been carried out at the Winfrith Technology Centre using its Molten Fuel Test Facilities to examine the initial interaction between a fuel melt and concrete. A molten fuel simulant consisting of 81% UO 2 and 19% Mo with a large superheat (T≅3600 K) was poured onto a basaltic concrete target. Thermocouple data indicate that there was an initial high rate of ablation. The test demonstrated that in the case of such high superheats, a vigorous interaction between the jet and the target takes place, with much of the impinging material ejected within the first few seconds. There was a depression eroded into the target by the jet. The experiment has subsequently been modeled at Culham Laboratory using a version of the CORCON MCCI (molten core-concrete interaction) computer code. The calculations were able to produce a representation of this effect. The results of the experiment and the calculation have been compared with jetting correlations, and reasonable agreement has been found. We conclude by advising caution when applying the results of this isolated test to more prototypic interactions. (orig.)
Report on the fiscal 1996 development of high efficient waste power generation technology; 1996 nendo kokoritsu haikibutsu hatsuden gijutsu kaihatsu hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The technical development was made by which high-temperature/high-pressure steam is generated in the incineration furnace using general waste, combustible industrial waste, etc. as fuel to generate power high efficiently, and reliability of the superheater, etc. was verified by the pilot plant. For it, the following were conducted: development of element technology (high-temperature/high-efficiency combustion furnace, corrosion resistant super heater materials, environmental load reduction technology) and the demonstration (demonstrative test in pilot plant, study of an optimum total system). In relation to the external circulation type fluidized bed furnace, reformation was made which enables simultaneous sampling of dioxins, etc. The combustion test was done using the reformed combustion testing furnace to obtain the data necessary for the study of formation/decomposition mechanism of dioxin. The amount of corrosion reduction of superheater sample material for pilot plant use was determined. A study was made of improvement of removal of dioxins and NOx in the pulse plasma exhaust gas treatment method. The pilot plant was installed. 10 refs., 205 figs., 79 tabs.
Texas flexible pavements and overlays : year 1 report, test sections, data collection, analyses, and data storage system.

Science.gov (United States)

2012-06-01

This five-year project was initiated to collect materials and pavement performance data on a minimum of 100 highway test sections around the State of Texas, incorporating both flexible pavements and overlays. Besides being used to calibrate and valid...
Testing Testing Testing.

Science.gov (United States)

Deville, Craig; O'Neill, Thomas; Wright, Benjamin D.; Woodcock, Richard W.; Munoz-Sandoval, Ana; Gershon, Richard C.; Bergstrom, Betty

1998-01-01

Articles in this special section consider (1) flow in test taking (Craig Deville); (2) testwiseness (Thomas O'Neill); (3) test length (Benjamin Wright); (4) cross-language test equating (Richard W. Woodcock and Ana Munoz-Sandoval); (5) computer-assisted testing and testwiseness (Richard Gershon and Betty Bergstrom); and (6) Web-enhanced testing…
Development of Computational Capabilities to Predict the Corrosion Wastage of Boiler Tubes in Advanced Combustion Systems

Energy Technology Data Exchange (ETDEWEB)

Kung, Steven; Rapp, Robert

2014-08-31

A comprehensive corrosion research project consisting of pilot-scale combustion testing and long-term laboratory corrosion study has been successfully performed. A pilot-scale combustion facility available at Brigham Young University was selected and modified to enable burning of pulverized coals under the operating conditions typical for advanced coal-fired utility boilers. Eight United States (U.S.) coals were selected for this investigation, with the test conditions for all coals set to have the same heat input to the combustor. In addition, the air/fuel stoichiometric ratio was controlled so that staged combustion was established, with the stoichiometric ratio maintained at 0.85 in the burner zone and 1.15 in the burnout zone. The burner zone represented the lower furnace of utility boilers, while the burnout zone mimicked the upper furnace areas adjacent to the superheaters and reheaters. From this staged combustion, approximately 3% excess oxygen was attained in the combustion gas at the furnace outlet. During each of the pilot-scale combustion tests, extensive online measurements of the flue gas compositions were performed. In addition, deposit samples were collected at the same location for chemical analyses. Such extensive gas and deposit analyses enabled detailed characterization of the actual combustion environments existing at the lower furnace walls under reducing conditions and those adjacent to the superheaters and reheaters under oxidizing conditions in advanced U.S. coal-fired utility boilers. The gas and deposit compositions were then carefully simulated in a series of 1000-hour laboratory corrosion tests, in which the corrosion performances of different commercial candidate alloys and weld overlays were evaluated at various temperatures for advanced boiler systems. Results of this laboratory study led to significant improvement in understanding of the corrosion mechanisms operating on the furnace walls as well as superheaters and reheaters in
Investigation on steam oxidation behaviour of TP347H FG Part I Exposure at 256 bar

DEFF Research Database (Denmark)

Jianmin, J; Montgomery, Melanie; Larsen, OH

2005-01-01

with the aforementioned steel in coal-fired boilers and this paper focuses on the steam oxidation behaviour for specimens tested at various metal temperatures for exposure times of 7700, 23000 and 30000 hours as investigated by light optical and scanning electron microscopy. The oxide present on the specimens is a duplex......The stainless steel TP347H FG is a candidate material for the final stage tubing of superheater and reheater sections of ultra supercritical boilers operated at steam temperatures up to 620C in the mild corrosion environments of coal-firing. A series of field tests has been conducted...... oxide, where the outer layer consists of two sub-layers, an iron oxide layer and an iron-nickel oxide layer; the inner layer is chromium rich chromium-iron-nickel oxide. Microstructure examination showed that for all these samples the varying grain size of subsurface metal affected the oxide thickness...
Benchmark test of MORSE-DD code using double-differential form cross sections

International Nuclear Information System (INIS)

Nakagawa, Masayuki; Mori, Takamasa; Ishiguro, Yukio

1985-02-01

The multi-group double-differential form cross sections (DDX) and the three dimensional Monte Carlo code MORSE-DD devised to utilize the DDX, which were developed for the fusion neutronics analysis, have been validated through many benchmark tests. All the problems tested have a 14 MeV neutron source. To compare the calculated results with the measured values, the following experiments were adopted as the benchmark problems; leakage neutron spectra from spheres composed of nine kinds of materials measured at LLNL, neutron angular spectra from the Li 2 O slab measured at FNS in JAERI, tritium production rate (TPR) in the graphite-reflected Li 2 O sphere measured at FNS and the TPR in the metallic Li sphere measured at KfK. In addition in order to test an accuracy of the calculation method in detail, spectra of neutrons scattered from a small sample and various reaction rates in a Li 2 O cylinder were compared between the present method and the continuous energy Monte Carlo method. The nuclear data files used are mainly ENDF/B4 and partly JENDL-3PR1. The tests were carried out through a comparison with the measured values and also with the results obtained from the conventional Legendre expansion method and the continuous energy Monte Carlo method. It is found that the results by the present method are more accurate than those by the conventional one and agree well with those by the continuous energy Monte Carlo calculations. Discrepancies due to the nuclear data are also discussed. (author)
Geomaterial characterizations of full scale pavement test sections for mechanistic analysis and design

CSIR Research Space (South Africa)

Kwon, J

2007-02-01

Full Text Available roller compactor. The compaction effort was monitored with nuclear density gauge and DCP measurements taken from each pavement test section. As-built density of each subgrade lift obtained using the nuclear gauge satisfied a minimum relative density... was monitored with a nuclear gauge to maintain a minimum 95% relative compaction in the field. 0 100 200 300 400 500 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 CBR (%) Pe n et ra tio n (m m ) Pe n et ra tio n (m m ) Figure 2...
Boiling hysteresis of impinging circular submerged jets with highly wetting liquids

International Nuclear Information System (INIS)

Zhou, D.W.; Ma, C.F.; Yu, J.

2004-01-01

An experimental study was carried out to characterize the boiling hysteresis of impinging circular submerged jets with highly wetting liquids. The effects of noncondensable gases and surface aging on boiling curves were considered. The present study focused on the effects of jet parameters (jet exit velocity, radial distance from the stagnation point and nozzle diameter) and fluid subcooling on incipient boiling superheat and superheat excursion, as well as the physical mechanism of boiling hysteresis. Results show that the incipient boiling superheat decreases only with fluid subcooling regardless of jet parameters, and that the superheat excursion increases with nozzle diameter and radial distance from the stagnation point and decreasing jet exit velocity and fluid subcooling. Boiling hysteresis occurs due to deactivation of vapor embryos within larger cavities. Three anomalous phenomena at boiling inception are recorded and discussed in terms of irregular activation of vapor embryos
Evaluated cross section libraries

International Nuclear Information System (INIS)

Maqurno, B.A.

1976-01-01

The dosimetry tape (ENDF/B-IV tape 412) was issued in a general CSEWG distribution, August 1974. The pointwise cross section data file was tested with specified reference spectra. A group averaged cross section data file (620 groups based on tape 412) was tested with the above spectra and the results are presented in this report
Testing a self-determination theory model of children's physical activity motivation: a cross-sectional study.

Science.gov (United States)

Sebire, Simon J; Jago, Russell; Fox, Kenneth R; Edwards, Mark J; Thompson, Janice L

2013-09-26

Understanding children's physical activity motivation, its antecedents and associations with behavior is important and can be advanced by using self-determination theory. However, research among youth is largely restricted to adolescents and studies of motivation within certain contexts (e.g., physical education). There are no measures of self-determination theory constructs (physical activity motivation or psychological need satisfaction) for use among children and no previous studies have tested a self-determination theory-based model of children's physical activity motivation. The purpose of this study was to test the reliability and validity of scores derived from scales adapted to measure self-determination theory constructs among children and test a motivational model predicting accelerometer-derived physical activity. Cross-sectional data from 462 children aged 7 to 11 years from 20 primary schools in Bristol, UK were analysed. Confirmatory factor analysis was used to examine the construct validity of adapted behavioral regulation and psychological need satisfaction scales. Structural equation modelling was used to test cross-sectional associations between psychological need satisfaction, motivation types and physical activity assessed by accelerometer. The construct validity and reliability of the motivation and psychological need satisfaction measures were supported. Structural equation modelling provided evidence for a motivational model in which psychological need satisfaction was positively associated with intrinsic and identified motivation types and intrinsic motivation was positively associated with children's minutes in moderate-to-vigorous physical activity. The study provides evidence for the psychometric properties of measures of motivation aligned with self-determination theory among children. Children's motivation that is based on enjoyment and inherent satisfaction of physical activity is associated with their objectively-assessed physical
An Experimental Study of Natural Circulation in a Loop with Parallel Flow Test Sections

Energy Technology Data Exchange (ETDEWEB)

Mathisen, R P; Eklind, O

1965-10-15

The dynamic behaviour of a natural circulation loop parallel round duct channels has been studied. The test sections were both electrically heated and the power distribution was uniform along the 4300 mm heated length of the 20 mm dia. channels. The inter channel interference and the threshold of flow instability were obtained by using a dynamically calibrated flowmeter in each channel. The pressure was 50 bars and the sub-cooling 6 deg C. The main parameters varied, were the flow restrictions in the one-phase and two-phase sections. The instability data were correlated to the resistance coefficients due to these restrictions. Theoretical calculations for parallel channels in natural circulation have been compared with the experimental results. For the conditions determined by the above mentioned magnitudes, the steady-state computations are in excellent agreement with experiment. The transients are also nearly similar, except for the resonance frequency which for the theoretical case is higher by an amount between 0.3 and 0.5 c.p.s.
An Experimental Study of Natural Circulation in a Loop with Parallel Flow Test Sections

International Nuclear Information System (INIS)

Mathisen, R.P.; Eklind, O.

1965-10-01

The dynamic behaviour of a natural circulation loop parallel round duct channels has been studied. The test sections were both electrically heated and the power distribution was uniform along the 4300 mm heated length of the 20 mm dia. channels. The inter channel interference and the threshold of flow instability were obtained by using a dynamically calibrated flowmeter in each channel. The pressure was 50 bars and the sub-cooling 6 deg C. The main parameters varied, were the flow restrictions in the one-phase and two-phase sections. The instability data were correlated to the resistance coefficients due to these restrictions. Theoretical calculations for parallel channels in natural circulation have been compared with the experimental results. For the conditions determined by the above mentioned magnitudes, the steady-state computations are in excellent agreement with experiment. The transients are also nearly similar, except for the resonance frequency which for the theoretical case is higher by an amount between 0.3 and 0.5 c.p.s

Diagnostic and laboratory test ordering in Northern Portuguese Primary Health Care: a cross-sectional study

Science.gov (United States)

Sá, Luísa; Teixeira, Andreia Sofia Costa; Tavares, Fernando; Costa-Santos, Cristina; Couto, Luciana; Costa-Pereira, Altamiro; Hespanhol, Alberto Pinto; Santos, Paulo

2017-01-01

Objectives To characterise the test ordering pattern in Northern Portugal and to investigate the influence of context-related factors, analysing the test ordered at the level of geographical groups of family physicians and at the level of different healthcare organisations. Design Cross-sectional study. Setting Northern Primary Health Care, Portugal. Participants Records about diagnostic and laboratory tests ordered from 2035 family physicians working at the Northern Regional Health Administration, who served approximately 3.5 million Portuguese patients, in 2014. Outcomes To determine the 20 most ordered diagnostic and laboratory tests in the Northern Regional Health Administration; to identify the presence and extent of variations in the 20 most ordered diagnostic and laboratory tests between the Groups of Primary Care Centres and between health units; and to study factors that may explain these variations. Results The 20 most ordered diagnostic and laboratory tests almost entirely comprise laboratory tests and account for 70.9% of the total tests requested. We can trace a major pattern of test ordering for haemogram, glucose, lipid profile, creatinine and urinalysis. There was a significant difference (P<0.001) in test orders for all tests between Groups of Primary Care Centres and for all tests, except glycated haemoglobin (P=0.06), between health units. Generally, the Personalised Healthcare Units ordered more than Family Health Units. Conclusions The results from this study show that the most commonly ordered tests in Portugal are laboratory tests, that there is a tendency for overtesting and that there is a large variability in diagnostic and laboratory test ordering in different geographical and organisational Portuguese primary care practices, suggesting that there may be considerable potential for the rationalisation of test ordering. The existence of Family Health Units seems to be a strong determinant in decreasing test ordering by Portuguese family
Thermal response test data of five quadratic cross section precast pile heat exchangers

Directory of Open Access Journals (Sweden)

Maria Alberdi-Pagola

2018-06-01

Full Text Available This data article comprises records from five Thermal Response Tests (TRT of quadratic cross section pile heat exchangers. Pile heat exchangers, typically referred to as energy piles, consist of traditional foundation piles with embedded heat exchanger pipes. The data presented in this article are related to the research article entitled “Comparing heat flow models for interpretation of precast quadratic pile heat exchanger thermal response tests” (Alberdi-Pagola et al., 2018 [1]. The TRT data consists of measured inlet and outlet temperatures, fluid flow and injected heat rate recorded every 10 min. The field dataset is made available to enable model verification studies.
Testing for Helicobacter pylori in dyspeptic patients suspected of peptic ulcer disease in primary care: cross sectional study

NARCIS (Netherlands)

Weijnen, C. F.; Numans, M. E.; de Wit, N. J.; Smout, A. J.; Moons, K. G.; Verheij, T. J.; Hoes, A. W.

2001-01-01

OBJECTIVES: To develop an easily applicable diagnostic scoring method to determine the presence of peptic ulcers in dyspeptic patients in a primary care setting; to evaluate whether Helicobacter pylori testing adds value to history taking. Design: Cross sectional study. SETTING: General
Properties and application of new bainitic and martensitic creep resistance steels

International Nuclear Information System (INIS)

Pasternak, J.; Dobrzanski, J.

2008-01-01

Supercritical operating parameters of lower emission power units, require novel creep resisting steels to be applied for boiler and pipe systems. Among them are T23 bainitic steels for water walls of boiler combustion chamber and martensitic VM12 steels for superheater coils were tested. RAFAKO S.A. has been co-operating with the Silesian Technical University in Katowice, the Institute of Welding and the Institute for Ferrous Metallurgy in Gliwice for several years now, initiating research and development programmes, implementing the new creep-resistant steels and actively participating in European programmes COST522 and COST536. This paper contains selected information and test results before implementation of the new creep-resistant steels, including: evaluation of working parameters, temperature conditions of main boiler components, which influence reliability and safety, selection of steels for furnace chamber components (approx. 2.5 % Cr) and steam superheater components (9-12 % Cr) destination, evaluation of the requested level of welded joints technological and strength properties, measurements and non-destructive examinations, evaluation of welded joints and HAZ structure by means of LM, TEM and SEM methods in the welding technology implementation process, evaluation of corrosion mechanisms and creep-resistance results - loss of service life - for selected evaporator and steam superheater components, as crucial elements in evaluation of reliability and safety of boiler equipment. Such an examination program includes assessment of steel structure stability during operation period in actual operational conditions. It was clearly shown that operation period have little impact on changes occurring in microstructure and other properties of examined steel grades. (author)
A thin-lip rupture of carbon steel superheater boiler tube

International Nuclear Information System (INIS)

Khalil, E.O.; Alzoye, K.S.; Elwaer, A.M.

1993-01-01

A ruptured A 42 medium carbon steel tube was collected by the engineering department in one of our steam power stations. Inspection of ruptured tube revealed a thin - lip fracture with brownish thin layer of oxide film on inner tube surfaces. There was no evidence of pitting, the outer surfaces of the tube exhibited a general oxidized conditions. A micro section taken near the fracture surface consists of ferrite and martensite, the amount of martensite decreased as we away from the fracture surface. Presence of martensite phase in the microstructure indicates that the tube material has been overheated. An erosion corrosion mechanism in conjunction with overheated. An erosion corrosion mechanism in conjunction with overheating resulted in strength deterioration with consequent premature failure. 4 fig., 1 tab
Obstetrical correlates of the first time cesarean section, compared with the repeated cesarean section

International Nuclear Information System (INIS)

Rukh, G.; Akhtar, S.

2007-01-01

To determine the clinical and epidemiological characteristics in patients having their first cesarean section (FCS) and compare it with findings in patients with repeated cesarean section (RCS). This study included all the women who gave birth by cesarean sections, 817 of the total 5992 deliveries, at this unit during the study period. Data on potential risk factors for the first cesarean section (FCS) and repeated cesarean section (RCS were extracted from medical records, which were reviewed and compared between these two groups of women. Data were statistically analyzed with student t-test for comparison between means and Chi-square test for comparison between percentages. Crude odds ratio (OR) with 95% confidence interval (95% CI) were calculated. Significance was taken at p 0.05). The frequency of first cesarean section and repeat cesarean section is high in our setup. Adequate following of the programs to diminish the percentage of FCS by curtailing its predisposing factors is needed. (author)
Seventeen years of LMFBR experience: Experimental Breeder Reactor II (EBR-II)

International Nuclear Information System (INIS)

Perry, W.H.; Lentz, G.L.; Richardson, W.J.; Wolz, G.C.

1982-01-01

Operating experience at EBR-II over the past 17 years has shown that a sodium-cooled pool-type reactor can be safely and efficiently operated and maintained. The reactor has performed predictably and benignly during normal operation and during both unplanned and planned plant upsets. The duplex-tube evaporators and superheaters have never experienced a sodium/water leak, and the rest of the steam-generating system has operated without incident. There has been no noticeable degradation of the heat transfer efficiency of the evaporators and superheaters, except for the one superheater replaced in 1981. There has been no need to perform any chemical cleaning of steam-system components
Nucleate pool boiling investigation on a silicon test section with micro-fabricated cavities

International Nuclear Information System (INIS)

Sanna, A.; Kenning, D.B.R.; Karayiannis, T.G.; Hutter, C.; Sefiane, K.; Nelson, R.A.

2009-01-01

The basic mechanisms of nucleate boiling are still not completely understood, in spite of the many numerical and experimental studies dedicated to the topic. The use of a hybrid code allows reasonable computational times for simulations of a solid plate with a large population of artificial micro-cavities with fixed distribution. This paper analyses the guidelines for the design, through numerical simulations, of the location and sizes of micro-fabricated cavities on a new silicon test section immersed in FC-72 at the saturation temperature for different pressures with an imposed heat flux applied at the back of the plate. Particular focus is on variations of wall temperature around nucleation sites. (author)
Exploring the Effect of Teaching Test-Taking Strategies on Intermediate Level Learners on Reading Section of Ielts; Learners’ Attitude in Focus

Directory of Open Access Journals (Sweden)

Hooshang Khoshsima

2018-04-01

Full Text Available Language proficiency tests have become common instruments to judge people based on their performance. Thus, the scores on language proficiency tests, such as the International English Language Testing System (IELTS or Teaching English as a Foreign Language (TOEFL, play a crucial role in the test-takers’ lives. Because of increasing demands on the part of students to get a good score on these tests, test preparatory courses have emerged. These preparatory courses, characteristically short and limited in terms of time, equip IELTS candidates with the skills required for passing the test, called test-taking strategies. The present study explored the effect of strategy teaching- namely wash-back effect on reading section of academic IELTS on intermediate learners in Iran. Besides, learners’ attitude toward the strategy teaching was investigated as well. According to the descriptive statistics and t-test results, those learners who received strategy teaching outperformed those who had not received strategy teaching in reading section of IELTS.According to t-test results, there was a significant difference between the mean scores of the two groups since the p value was lower than .05 (p < .001. Furthermore, the learners had positive attitudes toward receiving strategy teaching since there was a significant difference between the obtained mean score and the presupposed average because the p value was lower than .05.
Heat transfer in the in-pile test section and penetration region of 3-pin fuel test loop

Energy Technology Data Exchange (ETDEWEB)

Chi, Dae Young; Lee, Chung Young; Sim, Bong Shick; Park, Kook Nam; Park, Su Ki; Lee, Jong Min; Kim, Young Jin

2003-12-01

This report studies two types of normal heat transfer. One is the heat loss from the pressure vessel of In-Pile Test Section to HANARO pool water via IPS insulation gas gap. The other is the heat transfer of the Penetration Cooling Water System including the effect of the Foamglas insulator at the penetration region. The heat transfer from IPS insulation gas gap has been performed according to the detail design results from NUKEM. The heat loss also occurs at the concrete penetration region between the HANARO pool water and the FTL pipe gallery. The Foamglas insulator has been already installed at the MCW piping of the penetration region. This insulation effect has been reviewed. The Penetration Cooling Water System has been designed to fulfill the design requirement not to exceed the allowable temperature at the penetration concrete wall. The cooling ability and heat loss of PCW system has been reviewed with the insulation effect.
Testing a self-determination theory model of children’s physical activity motivation: a cross-sectional study

Science.gov (United States)

2013-01-01

Background Understanding children’s physical activity motivation, its antecedents and associations with behavior is important and can be advanced by using self-determination theory. However, research among youth is largely restricted to adolescents and studies of motivation within certain contexts (e.g., physical education). There are no measures of self-determination theory constructs (physical activity motivation or psychological need satisfaction) for use among children and no previous studies have tested a self-determination theory-based model of children’s physical activity motivation. The purpose of this study was to test the reliability and validity of scores derived from scales adapted to measure self-determination theory constructs among children and test a motivational model predicting accelerometer-derived physical activity. Methods Cross-sectional data from 462 children aged 7 to 11 years from 20 primary schools in Bristol, UK were analysed. Confirmatory factor analysis was used to examine the construct validity of adapted behavioral regulation and psychological need satisfaction scales. Structural equation modelling was used to test cross-sectional associations between psychological need satisfaction, motivation types and physical activity assessed by accelerometer. Results The construct validity and reliability of the motivation and psychological need satisfaction measures were supported. Structural equation modelling provided evidence for a motivational model in which psychological need satisfaction was positively associated with intrinsic and identified motivation types and intrinsic motivation was positively associated with children’s minutes in moderate-to-vigorous physical activity. Conclusions The study provides evidence for the psychometric properties of measures of motivation aligned with self-determination theory among children. Children’s motivation that is based on enjoyment and inherent satisfaction of physical activity is
Damping test results for straight sections of 3-inch and 8-inch unpressurized pipes. [PWR; BWR

Energy Technology Data Exchange (ETDEWEB)

Ware, A.G.; Thinnes, G.L.

1984-04-01

EG and G Idaho is assisting the Nuclear Regulatory Commission and the Pressure Vessel Research Committee in supporting a final position on revised damping values for structural analyses of nuclear piping systems. As part of this program, a series of vibrational tests on unpressurized 3-in. and 8-in. Schedule 40 carbon steel piping was conducted to determine the changes in structural damping due to various parametric effects. The 33-ft straight sections of piping were supported at the ends. Additionally, intermediate supports comprising spring, rod, and constant-force hangers, as well as a sway brace and snubbers, were used. Excitation was provided by low-force-level hammer impacts, a hydraulic shaker, and a 50-ton overhead crane for snapback testing. Data was recorded using acceleration, strain, and displacement time histories. This report presents test results showing the effect of stress level and type of supports on structural damping in piping.
Report of high efficiency waste power generation technology development in 1995; Kokoritsu haikibutsu hatsuden gijutsu kaihatsu (1995 nendo hokokusho)

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

High temperature and high pressure steam has been investigated for the high efficiency waste power generation technology development. The steam temperature below 300 centigrade is currently employed to avoid the corrosion of superheater, and the generating efficiency is less than 15%. Practical application of 500 centigrade and 100 kg/cm{sup 2} is planned by developing corrosion resistance materials. Environmental load reduction technology has been also developed. For the external circulation type fluidized bed furnace combustion tests using dummy waste in fiscal 1995, the temperature control at bag filter was effective for suppressing the dioxins. When using waste plastics, HCl could be reduced by blowing Ca compounds. Various Cr-Ni-Mo-based alloys have been developed as a corrosion resistance superheater tube material, and are currently tested. For the environmental load reduction technology, the development of pulse plasma exhaust gas treatment method has been continued from fiscal 1993. In fiscal 1995, this method was confirmed using a small-scale test unit, and also tested using a 5000 Nm{sup 3}/h bench-scale unit. The removal rates of dioxins at the outlet of bag filter were 99.8% and 99.3%, respectively. They were found to be affected greatly by the pulse waveform. 13 refs., 107 figs., 24 tabs.
Liquid-solid contact measurements using a surface thermocouple temperature probe in atmospheric pool boiling water

International Nuclear Information System (INIS)

Lee, L.Y.W.; Chen, J.C.; Nelson, R.A.

1984-01-01

Objective was to apply the technique of using a microthermocouple flush-mounted at the boiling surface for the measurement of the local-surface-temperature history in film and transition boiling on high temperature surfaces. From this measurement direct liquid-solid contact in film and transition boiling regimes was observed. In pool boiling of saturated, distilled, deionized water on an aluminum-coated copper surface, the time-averaged, local-liquid-contact fraction increased with decreasing surface superheat. Average contact duration increased monotonically with decreasing surface superheat, while frequency of liquid contact reached a maximum of approx. 50 contacts/s at a surface superheat of approx. 100 K and decreased gradually to 30 contacts/s near the critical heat flux. The liquid-solid contact duration distribution was dominated by short contacts 4 ms at low surface superheats, passing through a relatively flat contact duration distribution at about 80 0 K. Results of this paper indicate that liquid-solid contacts may be the dominant mechanism for energy transfer in the transition boiling process
The EBR-II steam generating system - operation, maintenance, and inspection

International Nuclear Information System (INIS)

Buschman, H.W.; Penney, W.H.; Longua, K.J.

2002-01-01

The Experimental Breeder Reactor II (EBR-II) has operated for 20 years at the Idaho National Engineering Laboratory near Idaho Falls. EBR-II is a Liquid Metal Fast Breeder Reactor (LMFBR) with integrated power producing capability. EBR-II has operated at a capacity factor over 70% in the past few years. Superheated steam is produced by eight natural circulation evaporators, two superheaters, and a conventional steam drum. Steam throttle conditions are 438 C and 8.62 MPa. The designs of the evaporators and superheaters are essentially identical; both are counterflow units with low pressure nonradioactive sodium on the shell side. During the 20 years of operation, components of the steam generator have been subjected to a variety of inspections including visual, dimensional, and ultrasonic. One superheater was removed from service because of anomalous performance and was replaced with an evaporator which was removed, examined, and converted into a superheater. Overall operating experience of the system has been excellent and essentially trouble free. Inspections have not revealed any conditions that are performance or life limiting. (author)
Seismic analysis of the in-pile test section

Energy Technology Data Exchange (ETDEWEB)

Lee, J. M.; Park, K. N.; Chi, D. Y.; Park, S. K.; Sim, B. S.; Ahn, S. H.; Lee, C. Y.; Kim, Y. J. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2004-07-01

This study gives the results of the seismic analysis of the IPS (In Pile Section) with lower bracket support. The results cover the natural frequency and seismic response of the IPS for the SSE and OBE events. An FE (Finite Element) model which includes the two vessels of the IPS and its support structure were analyzed by ABAQUS.
Wall adjustment strategy software for use with the NASA Langley 0.3-meter transonic cryogenic tunnel adaptive wall test section

Science.gov (United States)

Wolf, Stephen W. D.

1988-01-01

The Wall Adjustment Strategy (WAS) software provides successful on-line control of the 2-D flexible walled test section of the Langley 0.3-m Transonic Cryogenic Tunnel. This software package allows the level of operator intervention to be regulated as necessary for research and production type 2-D testing using and Adaptive Wall Test Section (AWTS). The software is designed to accept modification for future requirements, such as 3-D testing, with a minimum of complexity. The WAS software described is an attempt to provide a user friendly package which could be used to control any flexible walled AWTS. Control system constraints influence the details of data transfer, not the data type. Then this entire software package could be used in different control systems, if suitable interface software is available. A complete overview of the software highlights the data flow paths, the modular architecture of the software and the various operating and analysis modes available. A detailed description of the software modules includes listings of the code. A user's manual is provided to explain task generation, operating environment, user options and what to expect at execution.
Surface boiling of superheated liquid

Energy Technology Data Exchange (ETDEWEB)

Reinke, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-01-01

A basic vaporization mechanism that possibly affects the qualitative and quantitative prediction of the consequences of accidental releases of hazardous superheated liquids was experimentally and analytically investigated. The studies are of relevance for the instantaneous failure of a containment vessel filled with liquefied gas. Even though catastrophical vessel failure is a rare event, it is considered to be a major technological hazard. Modeling the initial phase of depressurisation and vaporization of the contents is an essential step for the subsequent analysis of the spread and dispersion of the materials liberated. There is only limited understanding of this inertial expansion stage of the superheated liquid, before gravity and atmospheric turbulence begin to dominate the expansion. This work aims at a better understanding of the vaporization process and to supply more precise source-term data. It is also intended to provide knowledge for the prediction of the behavior of large-scale releases by the investigation of boiling on a small scale. Release experiments with butane, propane, R-134a and water were conducted. The vaporization of liquids that became superheated by sudden depressurisation was studied in nucleation-site-free glass receptacles. Several novel techniques for preventing undesired nucleation and for opening the test-section were developed. Releases from pipes and from a cylindrical geometry allowed both linear one-dimensional, and radial-front two-dimensional propagation to be investigated. Releases were made to atmospheric pressure over a range of superheats. It was found that, above a certain superheat temperature, the free surface of the metastable liquid rapidly broke up and ejected a high-velocity vapor/liquid stream. The zone of intense vaporization and liquid fragmentation proceeded as a front that advanced into the test fluids. No nucleation of bubbles in the bulk of the superheated liquid was observed. (author) figs., tabs., refs.
Surface boiling of superheated liquid

International Nuclear Information System (INIS)

Reinke, P.

1997-01-01

A basic vaporization mechanism that possibly affects the qualitative and quantitative prediction of the consequences of accidental releases of hazardous superheated liquids was experimentally and analytically investigated. The studies are of relevance for the instantaneous failure of a containment vessel filled with liquefied gas. Even though catastrophical vessel failure is a rare event, it is considered to be a major technological hazard. Modeling the initial phase of depressurisation and vaporization of the contents is an essential step for the subsequent analysis of the spread and dispersion of the materials liberated. There is only limited understanding of this inertial expansion stage of the superheated liquid, before gravity and atmospheric turbulence begin to dominate the expansion. This work aims at a better understanding of the vaporization process and to supply more precise source-term data. It is also intended to provide knowledge for the prediction of the behavior of large-scale releases by the investigation of boiling on a small scale. Release experiments with butane, propane, R-134a and water were conducted. The vaporization of liquids that became superheated by sudden depressurisation was studied in nucleation-site-free glass receptacles. Several novel techniques for preventing undesired nucleation and for opening the test-section were developed. Releases from pipes and from a cylindrical geometry allowed both linear one-dimensional, and radial-front two-dimensional propagation to be investigated. Releases were made to atmospheric pressure over a range of superheats. It was found that, above a certain superheat temperature, the free surface of the metastable liquid rapidly broke up and ejected a high-velocity vapor/liquid stream. The zone of intense vaporization and liquid fragmentation proceeded as a front that advanced into the test fluids. No nucleation of bubbles in the bulk of the superheated liquid was observed. (author) figs., tabs., refs
Cross-sectional study of serum antibodies against Sarcocystis neurona in cats tested for antibodies against Toxoplasma gondii.

Science.gov (United States)

Rossano, Mary G; Murphy, Alice J; Vrable, Ruth A; Vanzo, Nicole E; Lewis, Stacy K; Sheline, Katherine D; Kaneene, John B; Mansfield, Linda S

2002-08-15

To determine apparent seroprevalence of antibodies against Sarcocystis neurona in a population of domestic cats previously tested for antibodies against Toxoplasma gondii. Cross-sectional study. Serum from 196 domestic cats. Banked serum samples submitted to the Michigan State University Animal Health Diagnostic Laboratory for T. gondii diagnostic testing were tested for antibodies against S. neurona by use of an indirect fluorescent antibody (IFA) test and a western blot test. Submission records were analyzed to determine descriptive statistics and test for associations between positive results of a test for S. neurona and other variables in the data set. 10 of 196 (5%) samples yielded positive results for antibodies against S. neurona by use of western blot analysis, whereas 27 samples yielded positive results by use of the IFA. No association was found between S. neurona western blot test results and T. gondii test results, age, sex, or the reason for T. gondii testing. The S. neurona IFA titer was positively and significantly associated with positive results of western blot analysis. Domestic cats are not likely to play a substantial role as intermediate hosts in the natural life cycle of S. neurona. Results indicate that natural infection of domestic cats may occur, and small animal practitioners should be aware of this fact when evaluating cats with neurologic disease. The S. neurona IFA test had lower specificity than western blot analysis.

Energy efficient control of a refrigeration plant

DEFF Research Database (Denmark)

Rasmussen, Henrik; Larsen, Lars F. S.

2009-01-01

This paper proposes a novel method for superheat and capacity control of refrigeration systems. The new idea is to control the superheat by the compressor speed and capacity by the refrigerant flow. A new low order nonlinear model of the evaporator is developed and used in a backstepping design...... and the methods are evaluated with respect to energy efficiency....
Test of the universal rise of hadronic total cross sections at super-high energies

International Nuclear Information System (INIS)

Ishida, Muneyuki; Igi, Keiji

2007-01-01

The increase of the total cross sections at very high energies described by log 2 (s/s 0 ) appears to be confirmed. In the analysis of the COMPETE collaboration in the Particle Data Group (2006), the Blog 2 (s/s 0 ) was assumed to extend the universal rise of all the total hadronic cross sections to reduce the number of adjustable parameters. We test if the assumption on the universality of B is justified, through investigation of the values of B for π ± p(K ± p) and pp,pp scatterings. We search for the simultaneous best fit to the σ tot and ρ ratios, using a constraint from the FESR of the P' type for π -+ p scatterings and constraints that are free from the unphysical regions for the pp, pp and K ± p scatterings. By including rich information of the low-energy scattering data owing to the use of FESR, the errors of the B parameters decrease especially for πp. The resulting value of B pp is consistent with B πp within two standard deviations, which appears to support the universality hypothesis. (orig.)
Section Preequating under the Equivalent Groups Design without IRT

Science.gov (United States)

Guo, Hongwen; Puhan, Gautam

2014-01-01

In this article, we introduce a section preequating (SPE) method (linear and nonlinear) under the randomly equivalent groups design. In this equating design, sections of Test X (a future new form) and another existing Test Y (an old form already on scale) are administered. The sections of Test X are equated to Test Y, after adjusting for the…
Portuguese Family Physicians' Awareness of Diagnostic and Laboratory Test Costs: A Cross-Sectional Study.

Directory of Open Access Journals (Sweden)

Luísa Sá

Full Text Available Physicians' ability to make cost-effective decisions has been shown to be affected by their knowledge of health care costs. This study assessed whether Portuguese family physicians are aware of the costs of the most frequently prescribed diagnostic and laboratory tests.A cross-sectional study was conducted in a representative sample of Portuguese family physicians, using computer-assisted telephone interviews for data collection. A Likert scale was used to assess physician's level of agreement with four statements about health care costs. Family physicians were also asked to estimate the costs of diagnostic and laboratory tests. Each physician's cost estimate was compared with the true cost and the absolute error was calculated.One-quarter (24%; 95% confidence interval: 23%-25% of all cost estimates were accurate to within 25% of the true cost, with 55% (95% IC: 53-56 overestimating and 21% (95% IC: 20-22 underestimating the true actual cost. The majority (76% of family physicians thought they did not have or were uncertain as to whether they had adequate knowledge of diagnostic and laboratory test costs, and only 7% reported receiving adequate education. The majority of the family physicians (82% said that they had adequate access to information about the diagnostic and laboratory test costs. Thirty-three percent thought that costs did not influence their decision to order tests, while 27% were uncertain.Portuguese family physicians have limited awareness of diagnostic and laboratory test costs, and our results demonstrate a need for improved education in this area. Further research should focus on identifying whether interventions in cost knowledge actually change ordering behavior, in identifying optimal methods to disseminate cost information, and on improving the cost-effectiveness of care.
Portuguese Family Physicians’ Awareness of Diagnostic and Laboratory Test Costs: A Cross-Sectional Study

Science.gov (United States)

Sá, Luísa; Costa-Santos, Cristina; Teixeira, Andreia; Couto, Luciana; Costa-Pereira, Altamiro; Hespanhol, Alberto; Santos, Paulo; Martins, Carlos

2015-01-01

Background Physicians’ ability to make cost-effective decisions has been shown to be affected by their knowledge of health care costs. This study assessed whether Portuguese family physicians are aware of the costs of the most frequently prescribed diagnostic and laboratory tests. Methods A cross-sectional study was conducted in a representative sample of Portuguese family physicians, using computer-assisted telephone interviews for data collection. A Likert scale was used to assess physician’s level of agreement with four statements about health care costs. Family physicians were also asked to estimate the costs of diagnostic and laboratory tests. Each physician’s cost estimate was compared with the true cost and the absolute error was calculated. Results One-quarter (24%; 95% confidence interval: 23%–25%) of all cost estimates were accurate to within 25% of the true cost, with 55% (95% IC: 53–56) overestimating and 21% (95% IC: 20–22) underestimating the true actual cost. The majority (76%) of family physicians thought they did not have or were uncertain as to whether they had adequate knowledge of diagnostic and laboratory test costs, and only 7% reported receiving adequate education. The majority of the family physicians (82%) said that they had adequate access to information about the diagnostic and laboratory test costs. Thirty-three percent thought that costs did not influence their decision to order tests, while 27% were uncertain. Conclusions Portuguese family physicians have limited awareness of diagnostic and laboratory test costs, and our results demonstrate a need for improved education in this area. Further research should focus on identifying whether interventions in cost knowledge actually change ordering behavior, in identifying optimal methods to disseminate cost information, and on improving the cost-effectiveness of care. PMID:26356625
Microstructure, texture and magnetic properties of strip-cast 1.3% Si non-oriented electrical steels

Energy Technology Data Exchange (ETDEWEB)

Zhang Yuanxiang, E-mail: yunboxu@126.com [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang (China); Xu Yunbo; Liu Haitao; Li Chenggang; Cao Guangming; Liu Zhenyu; Wang Guodong [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang (China)

2012-10-15

In this work, the evolution of microstructure, texture and magnetic properties of non-oriented 1.3% silicon steel processed using the twin-roll strip casting was investigated, especially under different solidification structures. A number of microstructures about the as-cast strips show that the initial solidification structure of casting a strip can be controlled by the melt superheats. The microstructures with the average grain size of {approx}100-400 {mu}m can be obtained in strips when the melt superheats are from 20 to 60 Degree-Sign C. A nearly random, diffuse, homogeneous texture under a low melt superheat, but comparatively developed {l_brace}100{r_brace} oriented grains are formed under a high melt superheat through the cast strip thickness. The relatively low core loss and high magnetic induction can be obtained in the cold rolled and annealed sheets when increasing the initial grain size of cast-strip. The textures in annealed sheets with coarse initial grain size are characterized by the relatively strong Goss component and {l_brace}001{r_brace} fiber but weak {gamma}-fiber component, which lead to the high permeability. - Highlights: Black-Right-Pointing-Pointer The superheat has an evident effect on the grain size and orientation of strip. Black-Right-Pointing-Pointer Developed Cube and Goss textures were formed in the annealed sheet. Black-Right-Pointing-Pointer High magnetic properties were obtained in the twin-rolled strip casting process.
Community engagement in sexual health and uptake of HIV testing and syphilis testing among MSM in China: a cross-sectional online survey.

Science.gov (United States)

Zhang, Tiange P; Liu, Chuncheng; Han, Larry; Tang, Weiming; Mao, Jessica; Wong, Terrence; Zhang, Ye; Tang, Songyuan; Yang, Bin; Wei, Chongyi; Tucker, Joseph D

2017-04-03

HIV and syphilis testing rates remain low among men who have sex with men (MSM) in low- and middle-income countries (LMICs). Community engagement has been increasingly used to promote HIV testing among key populations in high-income countries, often in settings with stronger civil society. This study aimed to assess socio-demographic, behavioural, and community engagement factors associated with HIV and syphilis testing among MSM in China. MSM ≥16 years old who had condomless sex in the past three months were recruited nationwide to complete a cross-sectional online survey in November 2015. Data were collected on socio-demographics, sexual behaviours, HIV testing, syphilis testing, and community engagement in sexual health. We defined community engagement in sexual health using six items assessing awareness and advocacy of sexual health programmes. The underlying factor structure of a 6-item community engagement scale was determined through exploratory factor analysis. Univariate and multivariable logistic regressions identified correlates of HIV and syphilis testing. 1189 MSM were recruited. 54% (647/1189) of men had ever tested for HIV and 30% (354/1189) had ever tested for syphilis. Factor analysis suggested three levels of community engagement (minimal, moderate, and substantial) and this model explained 79.5% of observed variance. A quarter (26%, 312/1189) reported none to minimal engagement, over one half (54%, 644/1189) reported moderate engagement, and a fifth (20%, 233/1189) reported substantial engagement. Multivariable logistic regression showed that MSM with greater community engagement in sexual health were more likely to have ever tested for HIV (substantial vs. no engagement: aOR 7.91, 95% CI 4.98-12.57) and for syphilis (substantial vs. no engagement: aOR 5.35, 95% CI 3.16-9.04). HIV and syphilis testing are suboptimal among MSM in China. Community engagement may be useful for promoting testing in China and should be considered in intervention
Investigating the Value of Section Scores for the "TOEFL iBT"® Test. "TOEFL iBT"® Research Report. TOEFL iBT-21. ETS Research Report RR-13-35

Science.gov (United States)

Sawaki, Yasuyo; Sinharay, Sandip

2013-01-01

This study investigates the value of reporting the reading, listening, speaking, and writing section scores for the "TOEFL iBT"® test, focusing on 4 related aspects of the psychometric quality of the TOEFL iBT section scores: reliability of the section scores, dimensionality of the test, presence of distinct score profiles, and the…
Computational simulation of the natural circulation occurring in an experimental test section of a pool type research reactor

Energy Technology Data Exchange (ETDEWEB)

Nascimento, Francisco R.T. do; Lima Junior, Carlos A.S.; Oliveira, Andre F.S. de; Affonso, Renato R.W.; Faccini, Jose L.H.; Moreira, Maria L., E-mail: rogerio.tdn@gmail.com, E-mail: souzalima_ca@ien.gov.br, E-mail: oliveira.afelipe@gmail.com, E-mail: raoniwa@yahoo.com.br, E-mail: faccini@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2015-07-01

The present work presents a computational simulation of the natural circulation phenomenon developing in an experimental test section of a pool type research reactor. The test section has been designed using a reduced scale in height 1:4.7 in relation to a pool type 30 MW research reactor prototype. It comprises a cylindrical vessel, which is opened to atmosphere, and representing the reactor pool; a natural circulation pipe, a lower plenum, and a heater containing electrical resistors in rectangular plate format, which represents the fuel elements, with a chimney positioned on the top of the resistor assembly. In the computational simulation, it was used a commercial CFD software, without any turbulence model. Besides, in the presence of the natural circulation, a laminar flow has been assumed and the equations of the mass conservation, momentum and energy were solved by the finite element method. In addition, the results of the simulation are presented in terms of velocities and temperatures differences, respectively: at inlet and outlet of the heater and of the natural circulation pipe. (author)
Computational simulation of the natural circulation occurring in an experimental test section of a pool type research reactor

International Nuclear Information System (INIS)

Nascimento, Francisco R.T. do; Lima Junior, Carlos A.S.; Oliveira, Andre F.S. de; Affonso, Renato R.W.; Faccini, Jose L.H.; Moreira, Maria L.

2015-01-01

The present work presents a computational simulation of the natural circulation phenomenon developing in an experimental test section of a pool type research reactor. The test section has been designed using a reduced scale in height 1:4.7 in relation to a pool type 30 MW research reactor prototype. It comprises a cylindrical vessel, which is opened to atmosphere, and representing the reactor pool; a natural circulation pipe, a lower plenum, and a heater containing electrical resistors in rectangular plate format, which represents the fuel elements, with a chimney positioned on the top of the resistor assembly. In the computational simulation, it was used a commercial CFD software, without any turbulence model. Besides, in the presence of the natural circulation, a laminar flow has been assumed and the equations of the mass conservation, momentum and energy were solved by the finite element method. In addition, the results of the simulation are presented in terms of velocities and temperatures differences, respectively: at inlet and outlet of the heater and of the natural circulation pipe. (author)
Analysis of benchmark experiments for testing the IKE multigroup cross-section libraries based on ENDF/B-III and IV

International Nuclear Information System (INIS)

Keinert, J.; Mattes, M.

1975-01-01

Benchmark experiments offer the most direct method for validation of nuclear cross-section sets and calculational methods. For 16 fast and thermal critical assemblies containing uranium and/or plutonium of different compositions we compared our calculational results with measured integral quantities, such as ksub(eff), central reaction rate ratios or fast and thermal activation (dis)advantage factors. Cause of the simple calculational modelling of these assemblies the calculations proved as a good test for the IKE multigroup cross-section libraries essentially based on ENDF/B-IV. In general, our calculational results are in excellent agreement with the measured values. Only with some critical systems the basic ENDF/B-IV data proved to be insufficient in calculating ksub(eff), probably due to Pu neutron data and U 238 fast capture cross-sections. (orig.) [de
Three-section expiratory CT

DEFF Research Database (Denmark)

Loeve, Martine; de Bruijne, Marleen; Hartmann, Ieneke C. J.

2012-01-01

. Longitudinal follow-up was performed with three sections. All images were deidentified and randomized, and TA was scored with the Brody II system and a new quantitative system. Statistical analysis included the Wilcoxon signed rank test, calculation of Spearman and intraclass correlation coefficients, and use......Purpose: To estimate the effect of the number of computed tomography (CT) sections on trapped air (TA) assessment in patients with cystic fibrosis (CF) by using an established scoring system and a new quantitative scoring system and to compare CT and pulmonary function test (PFT) estimates of TA...
Low upper-shelf toughness, high transition temperature test insert in HSST [Heavy Section Steel Technology] PTSE-2 [Pressurized Thermal Shock Experiment-2] vessel and wide plate test specimens: Final report

International Nuclear Information System (INIS)

Domian, H.A.

1987-02-01

A piece of A387, Grade 22 Class 2 (2-1/4 Cr - 1 Mo) steel plate specially heat treated to produce low upper-shelf (LUS) toughness and high transition temperature was installed in the side wall of Heavy Section Steel Technology (HHST) vessel V-8. This vessel is to be tested by the Oak Ridge National Laboratory (ORNL) in the Pressurized Thermal Shock Experiment-2 (PTSE-2) project of the HSST program. Comparable pieces of the plate were made into six wide plate specimens and other samples. These samples underwent tensile tests, Charpy tests, and J-integral tests. The results of these tests are given in this report
Feasibility of supervised self-testing using an oral fluid-based HIV rapid testing method: a cross-sectional, mixed method study among pregnant women in rural India.

Science.gov (United States)

Sarkar, Archana; Mburu, Gitau; Shivkumar, Poonam Varma; Sharma, Pankhuri; Campbell, Fiona; Behera, Jagannath; Dargan, Ritu; Mishra, Surendra Kumar; Mehra, Sunil

2016-01-01

HIV self-testing can increase coverage of essential HIV services. This study aimed to establish the acceptability, concordance and feasibility of supervised HIV self-testing among pregnant women in rural India. A cross-sectional, mixed methods study was conducted among 202 consenting pregnant women in a rural Indian hospital between August 2014 and January 2015. Participants were provided with instructions on how to self-test using OraQuick(®) HIV antibody test, and subsequently asked to self-test under supervision of a community health worker. Test results were confirmed at a government-run integrated counselling and testing centre. A questionnaire was used to obtain information on patient demographics and the ease, acceptability and difficulties of self-testing. In-depth interviews were conducted with a sub-sample of 35 participants to understand their experiences. In total, 202 participants performed the non-invasive, oral fluid-based, rapid test under supervision for HIV screening. Acceptance rate was 100%. Motivators for self-testing included: ease of testing (43.4%), quick results (27.3%) and non-invasive procedure (23.2%). Sensitivity and specificity were 100% for 201 tests, and one test was invalid. Concordance of test result interpretation between community health workers and participants was 98.5% with a Cohen's Kappa (k) value of k=0.566 with pwomen in rural India. Participants were supportive of making self-testing publicly available. Policy guidelines and implementation research are required to advance HIV self-testing for larger populations at scale.
Experience gained from shifting a PK-19 boiler to operate with increased superheating and with a load higher than its rated value

Science.gov (United States)

Kholshchev, V. V.

2011-08-01

Failures of steam superheater tubes occurred after the boiler was shifted to operate with a steam temperature of 540°C. The operation of the steam superheater became more reliable after it had been subjected to retrofitting. The modernization scheme is described. An estimate is given to the temperature operating conditions of tubes taking into account the thermal-hydraulic nonuniformity of their heating.
The R-134a energy efficiency problem

International Nuclear Information System (INIS)

Behrens, N.; Dekleva, T.W.; Hartley, J.G.; Murphy, F.T.; Powell, R.L.

1990-01-01

This paper examines the controversy over the relative energy efficiencies of R-134a and R-12, from a theoretical thermodynamic perspective. In this regard, the authors have used an in-house process flowsheeting program which allows to simulate the complete thermodynamic cycle, and investigate the effects of superheat and subcooling. Special attention is given to the suitable basis for comparing the energy efficiencies of different refrigerants calculated from thermodynamic data. Modelling experiments demonstrate the relative extent to which R-12 and R-134a respond differently to superheat and subcooling. With appropriate superheat and subcooling taken into consideration, such as applied in standard practice in the home appliance industry, R-134a can provide COP values essentially equivalent to that of R-12
The desorption of caesium from Peach Bottom HTGR steam generator materials

International Nuclear Information System (INIS)

Clark, M.J.

1979-03-01

The work at Harwell on the Peach Bottom End-of-Life Program in co-operation with the General Atomic Company (U.S.A.) is described. Materials taken from the Economiser, Evaporator and Superheater Sections of the Peach Bottom Unit No. 1. High Temperature Gas Cooled Reactor (HTGR) Heat Exchanger were placed in a reducing atmosphere comparable to the composition of an HTGR helium coolant gas, and the desorption of caesium isotopes measured under known conditions of flow, temperature and oxygen pressure. (author)
Design modification of the in-pile test section for increase of sealing capability

Energy Technology Data Exchange (ETDEWEB)

Hong, J T; Ahn, S H; Joung, C Y; Jeong, H Y; Lee, J M; Sim, B S [Department of Research Reactor Utilization and Development, Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2012-03-15

Since KAERI established the fuel test loop (FTL) at HANARO in 2009, KAERI has carried out several experiments to verify the performances of the equipment. Based on the experiments, the design modification of the In-Pile test Section (IPS) has been processed to improve some difficulties such as difficulty in ejecting the inner assembly of the IPS from the pressure vessel, difficulty of the sealing process of the cooling water, etc. At first, because the cooling water of HANARO in KAERI consists of an open-pool type, if a certain shock is generated during the disassembly process, the cooling water can be spattered out of the pool. Therefore, two jacking bolts will be added on the top flange part of the inner assembly to decrease the shock. Second, at the pressure boundary of the IPS where MI-cables go through, the brazing process has been used to seal out the cooling water. However, because the length of the IPS is up to 5.5 meters, it is too difficult and time consuming to carry out the brazing process at the end part of the IPS. Therefore, the brazing process will be replaced with the mechanical sealing structure to simplify the assembly process. (author)
Operation and post operative examinations on the 1 MW test section SDP-1

International Nuclear Information System (INIS)

Casalini, P.; Valentini, P.; Urbani, A.

1975-01-01

The tests carried out were essentially, of general interest and could regard the general Performance and the behavior of the materials. The last aspect was rather interesting as the steam generator coil consists of a steel which has not been yet homologated in Italy. As already specified, the geometry of the steam generator was somewhat particular: it consisted of a stainless steel (Type AISI 316) cylindrical envelope with a diameter of about 500 mm and about 4 m high, with inside an helicoidal duct having a rectangular section, also in AISI 316 stainless steel. Three helicoidal tubes with an outer diameter of 26,9 mm and a thickness of 5 mm, out of ferritic steel - Type Mannesman F 11 were arranged inside the duct. The rectangular duct was run through by sodium downwards, while water/steam was running through the three parallel tubes upwards. The main characteristics pertaining to the steam generator and the nominal operational data are given. All the tests carried out on the tube coil resulted in noticeable alteration due to operation in sodium. In particular, with regard to the absence of variation of the carbon content between the inner and outer side in all the specimens analyzed, one can conclude that no considerable mass transfer occurred in the tube
What do Key Stakeholders Think About HIV Self-Testing in Canada? Results from a Cross-Sectional Survey.

Science.gov (United States)

Pai, N Pant; Smallwood, M; Gulati, D; Lapczak, N; Musten, A; Gaydos, C; Johnston, C; Steben, M; Wong, T; Engel, N; Kim, J

2018-02-01

Human immunodeficiency virus (HIV) self-testing presents an empowering alternative to facility-based testing for reaching undiagnosed HIV infected individuals, but is not currently available in Canada. We surveyed stakeholders (clinical providers, public health professionals, researchers) engaged in HIV testing initiatives nationwide to identify the concerns, opportunities and challenges to implementing HIV self-testing in Canada. An online cross-sectional survey was disseminated by the Canadian Institutes of Health Research Centre for REACH 2.0 National HIV & sexually transmitted and blood borne infections working group to stakeholders nationwide, with a target sample size of 200. Quantitative and qualitative data were analyzed using a mixed-methods, respondent-informed approach, to inform subsequent HIV self-testing in a country where self-testing is not yet accessible. A total of 183 responses were received. A majority (70.7%) (128/181) felt that self-testing was a necessary investment to reach the undiagnosed. 64.6% (117/181) felt that self-tests should be made available to their clients and 71.5% (128/179) of respondents agreed that self-test instructions required improvements. However, 50% (90/180) felt that self-testing will pose an economic challenge to current HIV testing models. Regardless, 21% urged for timely action and availability of HIV self-tests. Thematic analyses reflected the following concerns: (a) need for affordable self-tests, (b) need for expedited, customized, and accessible linkages to counselling, (c) concern for patients to cope with positive self-test results, (d) accuracy of self-tests to detect acute HIV and (e) liability in the context of non-disclosure. Stakeholders agreed to the provision of an option of HIV self-testing to reach the undiagnosed individuals. Concerns regarding costs and accuracy of self-tests, expedited linkages to counselling, and integration of self-test within prevailing HIV testing models, will need to be

Work-related stress is associated with impaired neuropsychological test performance: a clinical cross-sectional study.

Science.gov (United States)

Eskildsen, Anita; Andersen, Lars Peter; Pedersen, Anders Degn; Vandborg, Sanne Kjær; Andersen, Johan Hviid

2015-01-01

Patients on sick leave due to work-related stress often complain about impaired concentration and memory. However, it is undetermined how widespread these impairments are, and which cognitive domains are most long-term stress sensitive. Previous studies show inconsistent results and are difficult to synthesize. The primary aim of this study was to examine whether patients with work-related stress complaints have cognitive impairments compared to a matched control group without stress. Our secondary aim was to examine whether the level of self-reported perceived stress is associated with neuropsychological test performance. We used a broad neuropsychological test battery to assess 59 outpatients with work-related stress complaints (without major depression) and 59 healthy controls. We matched the patients and controls pairwise by sex, age and educational level. Compared to controls, patients generally showed mildly reduced performance across all the measured domains of the neuropsychological test battery. However, only three comparisons reached statistical significance (p working memory. There were no statistical significant associations between self-reported perceived stress level and neuropsychological test performance. In conclusion, we recommend that cognitive functions should be considered when evaluating patients with work-related stress complaints, especially when given advice regarding return to work. Since this study had a cross-sectional design, it is still uncertain whether the impairments are permanent. Further study is required to establish causal links between work-related stress and cognitive deficits.
Home-based HIV testing for men preferred over clinic-based testing by pregnant women and their male partners, a nested cross-sectional study.

Science.gov (United States)

Osoti, Alfred Onyango; John-Stewart, Grace; Kiarie, James Njogu; Barbra, Richardson; Kinuthia, John; Krakowiak, Daisy; Farquhar, Carey

2015-07-30

Male partner HIV testing and counseling (HTC) is associated with enhanced uptake of prevention of mother-to-child HIV transmission (PMTCT), yet male HTC during pregnancy remains low. Identifying settings preferred by pregnant women and their male partners may improve male involvement in PMTCT. Participants in a randomized clinical trial (NCT01620073) to improve male partner HTC were interviewed to determine whether the preferred male partner HTC setting was the home, antenatal care (ANC) clinic or VCT center. In this nested cross sectional study, responses were evaluated at baseline and after 6 weeks. Differences between the two time points were compared using McNemar's test and correlates of preference were determined using logistic regression. Among 300 pregnant female participants, 54% preferred home over ANC clinic testing (34.0%) or VCT center (12.0%). Among 188 male partners, 68% preferred home-based HTC to antenatal clinic (19%) or VCT (13%). Men who desired more children and women who had less than secondary education or daily income Pregnant women and their male partners preferred home-based compared to clinic or VCT-center based male partner HTC. Home-based HTC during pregnancy appears acceptable and may improve male testing and involvement in PMTCT.
Advantages obtained in radiation protection when using computerized radiography tests - CR (digital) in processing plants

International Nuclear Information System (INIS)

Jose, Joao Carlos Videira; Milani, Hilton Sergio B.; Paes, Eliseu Almir de Oliveira; Boita, Mario de; Souza, Laercio de; Serra, Flavio Augusto dos Santos

2002-01-01

During the year 2000, the ARCtest initiated the development of the research for adapting the Computerized Radiography - CR, originally conceived for medical applications, for the Industry, trying initially to attend the requirements of the processing plants, concerning to the detection of deterioration mechanisms (evaluation of the piping integrity). Due to the obtained excellent results, the possibility of utilization the Computerized Radiography - CR in the radiographic inspection were studied during the shutdown of the Catalytic Cracking Unit of the PETROBRAS-REPLAN, specifically in the replacement of the CO boiler superheater, where a large number of the small diameter welded joints have been predicted
Process for distilling shales, peats, etc

Energy Technology Data Exchange (ETDEWEB)

Felizat, G

1922-01-09

The invention has for its object: a process for the distillation of shales, peats, and analogous products characterized by injecting across the substance a very rapid stream of superheated steam under pressure in order to effect a rapid removal of the products of distillation, to lower also the temperature at which it distills, to equalize the temperature throughout the mass, to hydrogenate the heavy hydrocarbons. An apparatus is put into operation characterized by the combination of a retort receiving the material to be distilled with a superheater for the steam, the combustion products which escape from the hearth of the superheater going to encircle the retort while the steam which comes off the superheater traverses this retort, the pressure of the steam being regulated by a convenient regulator; the products of the distillation result from the simultaneous action of the hot gases and steam on the contents of the retort being, on the other hand, separated at the outlet of this retort by means of cooling in a gas separator, a condenser, and part of the gas after being separated serving to heat the mentioned superheater.
Diagnosis of Heat Exchanger Tube Failure in Fossil Fuel Boilers Through Estimation of Steady State Operating Conditions

International Nuclear Information System (INIS)

Herszage, A.; Toren, M.

1998-01-01

Estimation of operating conditions for fossil fuel boiler heat exchangers is often required due to changes in working conditions, design modifications and especially for monitoring performance and failure diagnosis. Regular heat exchangers in fossil fuel boilers are composed of tube banks through which water or steam flow, while hot combustion (flue) gases flow outside the tubes. This work presents a top-down approach to operating conditions estimation based on field measurements. An example for a 350 MW unit superheater is thoroughly discussed. Integral calculations based on measurements for all unit heat exchangers (reheaters, superheaters) were performed first. Based on these calculations a scheme of integral conservation equations (lumped parameter) was then formulated at the single tube level. Steady state temperatures of superheater tube walls were obtained as a main output, and were compared to the maximum allowable operating temperatures of the tubes material. A combined lumped parameter - CFD (Computational Fluid Dynamics, FLUENT code) approach constitutes an efficient tool in certain cases. A brief report of such a case is given for another unit superheater. We conclude that steady state evaluations based on both integral and detailed simulations are a valuable monitoring and diagnosis tool for the power generation industry
The development of a capability for aerodynamic testing of large-scale wing sections in a simulated natural rain environment

Science.gov (United States)

Bezos, Gaudy M.; Cambell, Bryan A.; Melson, W. Edward

1989-01-01

A research technique to obtain large-scale aerodynamic data in a simulated natural rain environment has been developed. A 10-ft chord NACA 64-210 wing section wing section equipped with leading-edge and trailing-edge high-lift devices was tested as part of a program to determine the effect of highly-concentrated, short-duration rainfall on airplane performance. Preliminary dry aerodynamic data are presented for the high-lift configuration at a velocity of 100 knots and an angle of attack of 18 deg. Also, data are presented on rainfield uniformity and rainfall concentration intensity levels obtained during the calibration of the rain simulation system.
Prediction of mass fraction of agglomerated debris in a LWR severe accident

International Nuclear Information System (INIS)

Kudinov, P.; Davydov, M.

2011-01-01

Ex-vessel termination of accident progression in Swedish type Boiling Water Reactors (BWRs) is contingent upon efficacy of melt fragmentation and solidification in a deep pool of water below reactor vessel. When liquid melt reaches the bottom of the pool it can create agglomerated debris and “cake” regions that increase hydraulic resistance of the bed and affect coolability of the bed. This paper discusses development and application of a conservative-mechanistic approach to quantify mass fractions of agglomerated debris. Experimental data from the DEFOR-A (Debris Bed Formation and Agglomeration) tests with high superheat of binary oxidic simulant material melt is used for validation of the methods. Application of the approach to plant accident analysis suggests that melt superheat has less significant influence on agglomeration of the debris than jet penetration depth. The paper also discusses the impact of the uncertainty in the jet disintegration and penetration behavior on the agglomeration mode map. (author)
Ash Deposit Formation and Removal in a Straw and Wood Suspension-Fired Boiler

DEFF Research Database (Denmark)

Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming

). The shedding investigation was also made when the nearby plant sootblower (4m below) was working. It was identified that the mass uptake signal remained stable and the deposits in small pieces were continuously removed during 35% and 65% straw-firing. Previous findings of Vattenfall indicated that a mixture...... was limited to two weeks when 100% straw was fired due to ash deposition in the superheater region that has tube spacing specified for coal-firing (113mm). A series of 3-5 days deposit probe experiments were conducted utilizing 35 to 100% straw with wood on mass basis. The applied deposit probe was water...... two hours deposit mass uptake rate was 52.8 (g/m2/h), while it was 353.8 (g/m2/h) during 100% straw-firing. All tests in the superheater region for all applied straw shares indicated that with increase in straw share, final deposit mass uptake increased. The comparison of current and previous full...
Involving women in personalised decision-making on mode of delivery after caesarean section: the development and pilot testing of a patient decision aid.

Science.gov (United States)

Schoorel, E N C; Vankan, E; Scheepers, H C J; Augustijn, B C C; Dirksen, C D; de Koning, M; van Kuijk, S M J; Kwee, A; Melman, S; Nijhuis, J G; Aardenburg, R; de Boer, K; Hasaart, T H M; Mol, B W J; Nieuwenhuijze, M; van Pampus, M G; van Roosmalen, J; Roumen, F J M E; de Vries, R; Wouters, M G A J; van der Weijden, T; Hermens, R P M G

2014-01-01

To develop a patient decision aid (PtDA) for mode of delivery after caesarean section that integrates personalised prediction of vaginal birth after caesarean (VBAC) with the elicitation of patient preferences and evidence-based information. A PtDA was developed and pilot tested using the International Patients Decision Aid Standards (IPDAS) criteria. Obstetric health care in the Netherlands. A multidisciplinary steering group, an expert panel, and 25 future users of the PtDA, i.e. women with a previous caesarean section. The development consisted of a construction phase (definition of scope and purpose, and selection of content, framework, and format) and a pilot testing phase by interview. The process was supervised by a multidisciplinary steering group. Usability, clarity, and relevance. The construction phase resulted in a booklet including unbiased balanced information on mode of birth after caesarean section, a preference elicitation exercise, and tailored risk information, including a prediction model for successful VBAC. During pilot testing, visualisation of risks and clarity formed the main basis for revisions. Pilot testing showed the availability of tailored structured information to be the main factor involving women in decision-making. The PtDA meets 39 out of 50 IPDAS criteria (78%): 23 out of 23 criteria for content (100%) and 16 out of 20 criteria for the development process (80%). Criteria for effectiveness (n = 7) were not evaluated. An evidence-based PtDA was developed, with the probability of successful VBAC and the availability of structured information as key items. It is likely that the PtDA enhances the quality of decision-making on mode of birth after caesarean section. © 2013 Royal College of Obstetricians and Gynaecologists.
Peculiar high temperature corrosion of martensite alloy under impact of Estonian oil shale fly ash

Energy Technology Data Exchange (ETDEWEB)

Tallermo, H; Klevtsov, I [Thermal Engineering Department of Tallinn Technical University, Tallinn (Estonia)

1999-12-31

The superheaters` surfaces of oil shale steam boiler made of pearlitic and austenitic alloys, are subject to intensive corrosion, mainly due to presence of chlorine in external deposits. The applicability of martensitic alloys X1OCrMoVNb91 and X20CrMoV121 for superheaters is examined here and empirical equations allowing to predict alloys` corrosion resistance in the range of operational temperatures are established. Alloy X1OCrMoVNb91 is found been most perspective for superheaters of boilers firing fossil fuel that contain alkaline metals and chlorine. The abnormal dependence of corrosion resistance of martensitic alloys on temperature is revealed, namely, corrosion at 580 deg C in presence of oil shale fly ash is more intensive than at 620 deg C. (orig.) 2 refs.
Peculiar high temperature corrosion of martensite alloy under impact of Estonian oil shale fly ash

Energy Technology Data Exchange (ETDEWEB)

Tallermo, H.; Klevtsov, I. [Thermal Engineering Department of Tallinn Technical University, Tallinn (Estonia)

1998-12-31

The superheaters` surfaces of oil shale steam boiler made of pearlitic and austenitic alloys, are subject to intensive corrosion, mainly due to presence of chlorine in external deposits. The applicability of martensitic alloys X1OCrMoVNb91 and X20CrMoV121 for superheaters is examined here and empirical equations allowing to predict alloys` corrosion resistance in the range of operational temperatures are established. Alloy X1OCrMoVNb91 is found been most perspective for superheaters of boilers firing fossil fuel that contain alkaline metals and chlorine. The abnormal dependence of corrosion resistance of martensitic alloys on temperature is revealed, namely, corrosion at 580 deg C in presence of oil shale fly ash is more intensive than at 620 deg C. (orig.) 2 refs.
Integral tests of coupled multigroup neutron and gamma cross sections with fission and fusion sources

International Nuclear Information System (INIS)

Schriewer, J.; Hehn, G.; Mattes, M.; Pfister, G.; Keinert, J.

1978-01-01

Calculations were made for different benchmark experiments in order to test the coupled multigroup neutron and gamma library EURLIB-3 with 100 neutron groups and 20 gamma groups. In cooperation with EURATOM, Ispra, we produced this shielding library recently from ENDF/B-IV data for application in fission and fusion technology. Integral checks were performed for natural lithium, carbon, oxygen, and iron. Since iron is the most important structural material in nuclear technology, we started with calculations of iron benchmark experiments. Most of them are integral experiments of INR, Karlsruhe, but comparisons were also done with benchmark experiments from USA and Japan. For the experiments with fission sources we got satisfying results. All details of the resonances cannot be checked with flux measurements and multigroup cross sections used. But some averaged resonance behaviour of the measured and calculated fluxes can be compared and checked within the error limits given. We get greater differences in the calculations of benchmark experiments with 14 MeV neutron sources. For iron the group cross sections of EURLIB-3 produce an underestimation of the neutron flux in a broad energy region below the source energy. The conclusion is that the energy degradation by inelastic scattering is too strong. For fusion application the anisotropy of the inelastic scatter process must be taken into account, which isn't done by the processing codes at present. If this effect isn't enough, additional corrections have to be applied to the inelastic cross sections of iron in ENDF/B-IV. (author)
Self administered cognitive screening test (TYM) for detection of Alzheimer’s disease: cross sectional study

Science.gov (United States)

Pengas, George; Dawson, Kate; Clatworthy, Philip

2009-01-01

Objective To evaluate a cognitive test, the TYM (“test your memory”), in the detection of Alzheimer’s disease. Design Cross sectional study. Setting Outpatient departments in three hospitals, including a memory clinic. Participants 540 control participants aged 18-95 and 139 patients attending a memory clinic with dementia/amnestic mild cognitive impairment. Intervention Cognitive test designed to use minimal operator time and to be suitable for non-specialist use. Main outcome measures Performance of normal controls on the TYM. Performance of patients with Alzheimer’s disease on the TYM compared with age matched controls. Validation of the TYM with two standard tests (the mini-mental state examination (MMSE) and the Addenbrooke’s cognitive examination-revised (ACE-R)). Sensitivity and specificity of the TYM in the detection of Alzheimer’s disease. Results Control participants completed the TYM with an average score of 47/50. Patients with Alzheimer’s disease scored an average of 33/50. The TYM score shows excellent correlation with the two standard tests. A score of ≤42/50 had a sensitivity of 93% and specificity of 86% in the diagnosis of Alzheimer’s disease. The TYM was more sensitive in detection of Alzheimer’s disease than the mini-mental examination, detecting 93% of patients compared with 52% for the mini-mental state exxamination. The negative and positive predictive values of the TYM with the cut off of ≤42 were 99% and 42% with a prevalence of Alzheimer’s disease of 10%. Thirty one patients with non-Alzheimer dementias scored an average of 39/50. Conclusions The TYM can be completed quickly and accurately by normal controls. It is a powerful and valid screening test for the detection of Alzheimer’s disease. PMID:19509424
Modelling of limestone injection for SO2 capture in a coal fired utility boiler

International Nuclear Information System (INIS)

Kovacik, G.J.; Reid, K.; McDonald, M.M.; Knill, K.

1997-01-01

A computer model was developed for simulating furnace sorbent injection for SO 2 capture in a full scale utility boiler using TASCFlow TM computational fluid dynamics (CFD) software. The model makes use of a computational grid of the superheater section of a tangentially fired utility boiler. The computer simulations are three dimensional so that the temperature and residence time distribution in the boiler could be realistically represented. Results of calculations of simulated sulphur capture performance of limestone injection in a typical utility boiler operation were presented
A microfluidic approach to water-rock interactions using thin rock sections: Pb and U sorption onto thin shale and granite sections

Energy Technology Data Exchange (ETDEWEB)

Oh, Youn Soo [Institute of Mine Reclamation Technology, Mine Reclamation Corp., 2 Segye-ro, Wonju-si, Gangwon-do, 26464 (Korea, Republic of); Jo, Ho Young, E-mail: hyjo@korea.ac.kr [Department of Earth and Environmental Sciences, Korea University, Anam-dong, Seongbuk-gu, Seoul, 02841 (Korea, Republic of); Ryu, Ji-Hun; Kim, Geon-Young [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-gu, Daejeon, 34057 (Korea, Republic of)

2017-02-15

Highlights: • Microfluidic tests was used to investigate water-rock (mineral) interactions. • Pb and U sorption onto thin shale and granite sections was evaluated. • Pb removal by thin shale section is related primarily to Fe-containing minerals. • A slightly larger amount of U was removed onto the thin granite section with Fe-containing minerals. - Abstract: The feasibility of using microfluidic tests to investigate water-rock (mineral) interactions in fractures regarding sorption onto thin rock sections (i.e., shale and granite) of lead (Pb) and uranium (U) was evaluated using a synthetic PbCl{sub 2} solution and uranium-containing natural groundwater as fluids. Effluent composition and element distribution on the thin rock sections before and after microfluidic testing were analyzed. Most Pb removal (9.8 mg/cm{sup 2}) occurred within 3.5 h (140 PVF), which was 74% of the total Pb removal (13.2 mg/cm{sup 2}) at the end of testing (14.5 h, 560 PVF). Element composition on the thin shale sections determined by μ-XRF analysis indicated that Pb removal was related primarily to Fe-containing minerals (e.g., pyrite). Two thin granite sections (biotite rich, Bt-R and biotite poor, Bt-P) exhibited no marked difference in uranium removal capacity, but a slightly higher amount of uranium was removed onto the thin Bt-R section (266 μg/cm{sup 2}) than the thin Bt-P section (240 μg/cm{sup 2}) within 120 h (4800 PVF). However, uranium could not be detected by micro X-ray fluorescence (μ-XRF) analysis, likely due to the detection limit. These results suggest that microfluidic testing on thin rock sections enables quantitative evaluation of rock (mineral)-water interactions at the micro-fracture or pore scale.
HIV testing among men who have sex with men in Tijuana, Mexico: a cross-sectional study.

Science.gov (United States)

Pines, Heather A; Goodman-Meza, David; Pitpitan, Eileen V; Torres, Karla; Semple, Shirley J; Patterson, Thomas L

2016-02-04

HIV testing is critical to the delivery of comprehensive HIV prevention and care services, yet coverage of sexual minorities by HIV testing programmes remains insufficient in many low- and middle-income countries, including Mexico. The objective of this study was to identify the prevalence and correlates of HIV testing among men who have sex with men (MSM) in Tijuana, Mexico. We conducted a cross-sectional study (2012-2013) among 189 MSM recruited via respondent-driven sampling (RDS). RDS-weighted logistic regression was used to identify correlates of prior HIV testing. RDS-adjusted prevalence of prior and recent (≤ 12 months) HIV testing was 63.5% (95% CI 51.9% to 73.5%) and 36.8% (95% CI 25.4% to 46.4%), respectively. Prior HIV testing was positively associated with older age (adjusted OR (AOR)=1.09, 95% CI 1.04 to 1.15), being born in Tijuana (AOR=2.68, 95% CI 1.05 to 6.86), higher levels of education (AOR=2.65, 95% CI 1.08 to 6.53), identifying as homosexual or gay (AOR=3.73, 95% CI 1.48 to 9.42), being more 'out' about having sex with men (AOR=1.28, 95% CI:1.02 to 1.62), and a history of sexual abuse (AOR=3.24, 95% CI 1.06 to 9.86). Prior HIV testing was negatively associated with reporting more condomless anal intercourse acts (past 2 months) (AOR=0.95, 95% CI 0.92 to 0.98) and greater internalised homophobia (AOR=0.92, 95% CI 0.86 to 0.99). Our findings indicate an urgent need for expanded HIV testing services for MSM in Tijuana. Innovative, non-stigmatising, confidential HIV testing interventions targeted at young, less educated, migrant and non-gay identifying MSM may facilitate HIV testing and timely linkage to HIV care and treatment within this population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
The effect of inlet flow oscillations on reflooding of a tubular test section

International Nuclear Information System (INIS)

Oh, S.; Banerjee, S.; Yadigaroglu, G.

1983-01-01

The reflooding of a vertical channel under oscillatory inlet flow conditions has been investigated experimentally. Compared to constant injection, oscillations always increase the liquid carryover in the early stages of reflooding. As reflooding progresses, the enhancement diminishes. The crossover point roughly coincides with saturation of the liquid at the quench front (QF). The higher liquid carryover at the beginning increases downstream heat transfer and speeds up QF propagation. But this higher liquid carryover, in turn, reduces the test section mass accumulation rate and delays QF propagation at later stages. The enhancement of liquid carryover, and the early increase and subsequent decrease in quench velocity are all accentuated as the oscillation amplitude and frequency increase. Large amplitude oscillations change the characteristics of QF propagation and the heat transfer immediately downstream of QF substantially. Correlations based on constant-injection reflooding data are not adequate, even if they are applied on an average local-conditions basis
Some aspects of metallurgical assessment of boiler tubes-Basic principles and case studies

International Nuclear Information System (INIS)

Chaudhuri, Satyabrata

2006-01-01

Microstructural changes in boiler tubes during prolong operation at high temperature and pressure decrease load bearing capacity limiting their useful lives. When the load bearing capacity falls below a critical level depending on operating parameters and tube geometry, failure occurs. In order to avoid such failures mainly from the view point of economy and safety, this paper describes some basic principles behind remaining life assessment of service exposed components and also a few case studies related to failure of a reheater tube of 1.25Cr-0.5Mo steel, a carbon steel tube and final superheater tubes of 2.25Cr-1Mo steel and remaining creep life assessment of service exposed but unfailed platen superheater and reheater tubes of 2.25Cr-1Mo steel. Sticking of fly ash particles causing reduction in effective tube wall thickness is responsible for failure of reheater tubes. Decarburised metal containing intergranular cracks at the inner surface of the carbon steel tube exhibiting a brittle window fracture is an indicative of hydrogen embrittlement responsible for this failure. In contrast, final superheater tube showed that the failure took place due to short-term overheating. The influence of prolong service revealed that unfailed reheater tubes exhibit higher tensile properties than that of platen superheater tubes. In contrast both the tubes at 50 MPa meet the minimum creep rupture properties when compared with NRIM data. The remaining creep life of platen superheater tube as estimated at 50 MPa and 570 deg. C (1058 o F) is more than 10 years and that of reheater tube at 50 MPa and 580 deg. C (1076 o F) is 9 years
Comparison between SRAM SEE cross-sections from ion beam testing with those obtained using a new picosecond pulsed laser facility

International Nuclear Information System (INIS)

Jones, R.; Chugg, A.M.; Jones, C.M.S.; Duncan, P.H.; Dyer, C.S.; Sanderson, C.

1999-01-01

A laser system has been designed to be capable of delivering large numbers of pulses across a micro-chip die under computer control, so as rapidly to generate upset and latch-up cross-section curves, in order to provide an efficient screening tool for SEE (single event effect) susceptibility. The system has been automated to make screening of parts for use in an SEE environment fast, efficient and inexpensive. A comparison between ion beam test results and laser test results has been used to develop initial calibrations between laser energy and LET (linear energy transfer)
Neutron integral test of graphite cross sections in MeV energy region for the JENDL-3T through an analysis of WINFRITH shielding experiment

International Nuclear Information System (INIS)

Ueki, Kohtaro; Sakurai, Kiyoshi.

1988-01-01

The neutron integral tests of graphite cross sections in MeV neutron energy region for the ENDF/B-IV, JENDL-2, JENDL-3PR1 and -3T were performed through the Monte Carlo analysis of the graphite shielding experiment at the WINFRITH. The measured values were on the reaction rates of 115 In(n,n') 115m In, 27 Al(n,α) 24 Na, 32 S(n,p) 32 P, and 103 Rh(n,n') 103m Rh threshold detectors located in the graphite slabs, so that the experiment on the graphite was good at the integral test of neutron cross sections in MeV energy resion. (author)

Secondary Electron Yield Measurements and Groove Chambers Tests in the PEP-II Beam Line Straights Sections

International Nuclear Information System (INIS)

Pivi, M

2008-01-01

Beam instability caused by the electron cloud has been observed in positron and proton storage rings and it is expected to be a limiting factor in the performance of the positron Damping Ring (DR) of future Linear Colliders such as ILC and CLIC [1, 2]. In the Positron Low Energy Ring (LER) of the PEP-II accelerator, we have installed vacuum chambers with rectangular grooves in a straight magnetic-free section to test this promising possible electron cloud mitigation technique. We have also installed a special chamber to monitor the secondary electron yield of TiN and TiZrV (NEG) coating, Copper, Stainless Steel and Aluminum under the effect of electron and photon conditioning in situ in the beam line. In this paper, we describe the ongoing R and D effort to mitigate the electron cloud effect for the ILC damping ring, the latest results on in situ secondary electron yield conditioning and recent update on the groove tests in PEP-II
Non-linear and adaptive control of a refrigeration system

DEFF Research Database (Denmark)

Rasmussen, Henrik; Larsen, Lars F. S.

2011-01-01

are capable of adapting to variety of systems. This paper proposes a novel method for superheat and capacity control of refrigeration systems; namely by controlling the superheat by the compressor speed and capacity by the refrigerant flow. A new low order nonlinear model of the evaporator is developed......In a refrigeration process heat is absorbed in an evaporator by evaporating a flow of liquid refrigerant at low pressure and temperature. Controlling the evaporator inlet valve and the compressor in such a way that a high degree of liquid filling in the evaporator is obtained at all compressor...... capacities ensures a high energy efficiency. The level of liquid filling is indirectly measured by the superheat. Introduction of variable speed compressors and electronic expansion valves enables the use of more sophisticated control algorithms, giving a higher degree of performance and just as important...
Steam turbine installations

International Nuclear Information System (INIS)

Bainbridge, A.

1976-01-01

The object of the arrangement described is to enable raising steam for driving steam turbines in a way suited to operating with liquid metals, such as Na, as heat transfer medium. A preheated water feed, in heat transfer relationship with the liquid metals, is passed through evaporator and superheater stages, and the superheated steam is supplied to the highest pressure stage of the steam turbine arrangement. Steam extracted intermediate the evaporator and superheater stages is employed to provide reheat for the lower pressure stage of the steam turbine. Only a major portion of the preheated water feed may be evaporated and this portion separated and supplied to the superheater stage. The feature of 'steam to steam' reheat avoids a second liquid metal heat transfer and hence represents a simplification. It also reduces the hazard associated with possible steam-liquid metal contact. (U.K.)
Psychosocial determinants of HIV testing across stages of change in Spanish population: a cross-sectional national survey

Directory of Open Access Journals (Sweden)

Maria Jose Fuster-RuizdeApodaca

2017-03-01

Full Text Available Abstract Background The goal of this research is to study the psychosocial determinants of HIV-testing as a function of the decision or change stage concerning this health behavior. The determinants considered in the major ongoing health models and the stages contemplated in the Precaution Adoption Process Model are analysed. Methods A cross-sectional survey was administered to 1,554 people over 16 years of age living in Spain by a computer-assisted telephone interview (CATI. The sample design was randomised, with quotas of sex and age. The survey measured various psychosocial determinants of health behaviors considered in the main cognitive theories, the interviewees' stage of change concerning HIV-testing (lack of awareness, decision not to act, decision to act, action, maintenance, and abandonment, and the signal for the action of getting tested or the perceived barriers to being tested. Results Approximately two thirds of the population had not ever had the HIV test. The predominant stage was lack of awareness. The most frequently perceived barriers to testing were related to the health system and to the stigma. We also found that the psychosocial determinants studied differed depending on the respondents' stage of change. Perception of risk, perceived self-efficacy, proximity to people who had been tested, perceived benefits of knowing the diagnosis, and a positive instrumental and emotional attitude were positively associated with the decision and maintenance of testing behavior. However, unrealistic underestimation of the risk of HIV infection, stereotypes about the infection, and the perceived severity of HIV were associated with the decision not to be tested. Conclusions There are various sociocognitive and motivational profiles depending on people’s decision stage concerning HIV-testing. Knowing this profile may allow us to design interventions to influence the psychosocial determinants that characterise each stage of change.
Psychosocial determinants of HIV testing across stages of change in Spanish population: a cross-sectional national survey.

Science.gov (United States)

Fuster-RuizdeApodaca, Maria Jose; Laguia, Ana; Molero, Fernando; Toledo, Javier; Arrillaga, Arantxa; Jaen, Angeles

2017-03-07

The goal of this research is to study the psychosocial determinants of HIV-testing as a function of the decision or change stage concerning this health behavior. The determinants considered in the major ongoing health models and the stages contemplated in the Precaution Adoption Process Model are analysed. A cross-sectional survey was administered to 1,554 people over 16 years of age living in Spain by a computer-assisted telephone interview (CATI). The sample design was randomised, with quotas of sex and age. The survey measured various psychosocial determinants of health behaviors considered in the main cognitive theories, the interviewees' stage of change concerning HIV-testing (lack of awareness, decision not to act, decision to act, action, maintenance, and abandonment), and the signal for the action of getting tested or the perceived barriers to being tested. Approximately two thirds of the population had not ever had the HIV test. The predominant stage was lack of awareness. The most frequently perceived barriers to testing were related to the health system and to the stigma. We also found that the psychosocial determinants studied differed depending on the respondents' stage of change. Perception of risk, perceived self-efficacy, proximity to people who had been tested, perceived benefits of knowing the diagnosis, and a positive instrumental and emotional attitude were positively associated with the decision and maintenance of testing behavior. However, unrealistic underestimation of the risk of HIV infection, stereotypes about the infection, and the perceived severity of HIV were associated with the decision not to be tested. There are various sociocognitive and motivational profiles depending on people's decision stage concerning HIV-testing. Knowing this profile may allow us to design interventions to influence the psychosocial determinants that characterise each stage of change.
Analisa Efisiensi Water Tube Boiler Berbahan Bakar Fiber, Cangkang Sawit dan Kulit Kayu Menggunakan Metode Langsung

OpenAIRE

Gaol, Dosma Putra Lumban

2016-01-01

Some of the factors that affect the efficiency of the boiler is a superheater pressure, water feed temperature, steam temperature, the amount of steam produced, the amount of fuel consumption and calorific value fuel combustion. Steamtab chemicallogic use companion software to calculate the value of enthalpy. The aim of this study is to get relations variations in pressure superheater with boiler efficiency, the relationship of variation of temperature feed water to the boiler efficiency, the...
Laterality judgments in people with low back pain--A cross-sectional observational and test-retest reliability study.

Science.gov (United States)

Linder, Martin; Michaelson, Peter; Röijezon, Ulrik

2016-02-01

Disruption of cortical representation, or body schema, has been indicated as a factor in the persistence and recurrence of low back pain (LBP). This has been observed through impaired laterality judgment ability and it has been suggested that this ability is affected in a spatial rather than anatomical manner. We compared laterality judgment performance of foot and trunk movements between people with LBP with or without leg pain and healthy controls, and investigated associations between test performance and pain. We also assessed the test-retest reliability of the Recognise Online™ software when used in a clinical and a home setting. Cross-sectional observational and test-retest study. Thirty individuals with LBP and 30 healthy controls performed judgment tests of foot and trunk laterality once supervised in a clinic and twice at home. No statistically significant group differences were found. LBP intensity was negatively related to trunk laterality accuracy (p = 0.019). Intraclass correlation values ranged from 0.51 to 0.91. Reaction time improved significantly between test occasions while accuracy did not. Laterality judgments were not impaired in subjects with LBP compared to controls. Further research may clarify the relationship between pain mechanisms in LBP and laterality judgment ability. Reliability values were mostly acceptable, with wide and low confidence intervals, suggesting test-retest reliability for Recognise Online™ could be questioned in this trial. A significant learning effect was observed which should be considered in clinical and research application of the test. Copyright © 2015 Elsevier Ltd. All rights reserved.
Demonstration of the test-retest reliability and sensitivity of the Lower Limb Functional Index-10 as a measure of functional recovery post burn injury: a cross-sectional repeated measures study design.

Science.gov (United States)

Ryland, Margaret E; Grisbrook, Tiffany L; Wood, Fiona M; Phillips, Michael; Edgar, Dale W

2016-01-01

Lower limb burns can significantly delay recovery of function. Measuring lower limb functional outcomes is challenging in the unique burn patient population and necessitates the use of reliable and valid tools. The aims of this study were to examine the test-retest reliability, sensitivity, and internal consistency of Sections 1 and 3 of the Lower Limb Functional Index-10 (LLFI-10) questionnaire for measuring functional ability in patients with lower limb burns over time. Twenty-nine adult patients who had sustained a lower limb burn injury in the previous 12 months completed the test-retest procedure of the study. In addition, the minimal detectable change (MDC) was calculated for Section 1 and 3 of the LLFI-10. Section 1 is focused on the activity limitations experienced by patients with a lower limb disorder whereas Section 3 involves patients indicating their current percentage of pre-injury duties. Section 1 of the LLFI-10 demonstrated excellent test-retest reliability (intra-class correlation coefficient (ICC) 0.98, 95 % CI 0.96-0.99) whilst Section 3 demonstrated high test-retest reliability (ICC 0.88, 95 % CI 0.79-0.94). MDC scores for Sections 1 and 3 were 1.27 points and 30.22 %, respectively. Internal consistency was demonstrated with a significant negative association (r s = -0.83) between Sections 1 and 3 of the LLFI-10 (p reliable for measuring functional ability in patients who have sustained lower limb burns in the previous 12 months, and furthermore, Section 1 is sensitive to changes in patient function over time.
Knowledge and perceptions of couples' voluntary counseling and testing in urban Rwanda and Zambia: a cross-sectional household survey.

Directory of Open Access Journals (Sweden)

April L Kelley

2011-05-01

Full Text Available Most incident HIV infections in sub-Saharan Africa occur between cohabiting, discordant, heterosexual couples. Though couples' voluntary HIV counseling and testing (CVCT is an effective, well-studied intervention in Africa, <1% of couples have been jointly tested.We conducted cross-sectional household surveys in Kigali, Rwanda (n = 600 and Lusaka, Zambia (n = 603 to ascertain knowledge, perceptions, and barriers to use of CVCT.Compared to Lusaka, Kigali respondents were significantly more aware of HIV testing sites (79% vs. 56%; had greater knowledge of HIV serodiscordance between couples (83% vs. 43%; believed CVCT is good (96% vs. 72%; and were willing to test jointly (91% vs. 47%. Stigma, fear of partner reaction, and distance/cost/logistics were CVCT barriers.Though most respondents had positive attitudes toward CVCT, the majority were unaware that serodiscordance between cohabiting couples is possible. Future messages should target gaps in knowledge about serodiscordance, provide logistical information about CVCT services, and aim to reduce stigma and fear.
FIZCON, ENDF/B Cross-Sections Redundancy Check

International Nuclear Information System (INIS)

Dunford, Charles L.

2007-01-01

1 - Description of program or function: FIZCON is a program for checking that an evaluated data file has valid data and conforms to recommended procedures. Version 7.01 (April 2005): set success flag after return from beginning; fixed valid level check for an isomer; fixed subsection energy range test in ckf9; changed lower limit on potential scattering test; fixed error in j-value test when l=0 and i=0; added one more significant figure to union grid check and sum up output messages; partial fission cross sections mt=19,20,21 and 38 did not require secondary energy distributions in file 5; corrected product test for elastic scattering; moved potential scattering test to psyche. Version 7.02 (May 2005): Fixed resonance parameter sum test. 2 - Method of solution: FIZCON can recognise the difference between ENDF-6 and ENDF-5 formats and performs its tests accordingly. Some of the tests performed include: data arrays are in increasing energy order; resonance parameter widths add up to the total; Q-values are reasonable and consistent; no required sections are missing and all cover the proper energy range; secondary distributions are normalized to 1.0; energy conservation in decay spectra. Optional tests can be performed to check the redundant cross sections, and algorithms can be used to check for possible incorrect entry of data values (Deviant Point test)
Overview of the computerized adaptive testing special section

Directory of Open Access Journals (Sweden)

Vicente Ponsoda

2000-01-01

Full Text Available Presentación de la sección monográfica sobre test adaptativos informatizados. Este artículo proporciona una visión conjunta de la sección especial de Psicológica sobre tests adaptativos informatizados. Se presenta también una breve introducción al tema. De cada artículo se muestran sus principales resultados, las conexiones con los demás trabajos de la sección especial y el tema de investigación con el que está más relacionado.
Application of composite tubes in power plants

International Nuclear Information System (INIS)

Toernblom, H.; Egnell, L.; Gullberg, R.

1975-01-01

Composite tubes with metallurgical bond are now being used on an industrial scale in recovery boilers. Service trials in power plants are viewed and the possibilities to solve fireside corrosion problems in the boiler and superheater sections are discussed. The present and potential future application in nuclear power plants is summarized. A brief presentation of the manufacture and fabrication of composite tubes is made and specific material properties are discussed. Composite tubes are concluded to be an established product and a useful means of meeting conflicting material requirements under severe service conditions. (author)
Steam generator materials constraints in UK design gas-cooled reactors

International Nuclear Information System (INIS)

James, D.W.

1988-01-01

A widely reported problem with Magnox-type reactors was the oxidation of carbon steel components in gas circuits and steam generators. The effects of temperature, pressure, gas composition and steel composition on oxidation kinetics have been determined, thus allowing the probabilities of failure of critical components to be predicted for a given set of operating conditions. This risk analysis, coupled with regular inspection of reactor and boiler internals, has allowed continued operation of all U.K. Magnox plant. The Advanced Gas Cooled Reactor (AGR) is a direct development of the Magnox design. The first four AGRs commenced operation in 1976, at Hinkley Point 'B' and at Hunterston 'B'. All known materials problems with the steam generators have been diagnosed and solved by the development of appropriate operational strategies, together with minor plant modifications. Materials constraints no longer impose any restrictions to full load performance from the steam generators throughout the predicted life of the plant. Problems discussed in detail are: 1. oxidation of the 9 Cr - 1 Mo superheater. 2. Stress corrosion of the austenitic superheater. 3. Creep of the transition joints between the 9 Cr - 1 Mo and austenitic sections. With the 9 Cr - 1 Mo oxidation maximum temperature restriction virtually removed and creep constraints properly quantified, boiler operation in now favourably placed. Stress corrosion research has allowed the risk of tube failure to be related to time, temperature, stress and chemistry. As a result, the rigorous 'no wetting' policy has been relaxed for the normally high quality AGR feedwater, and the superheat margin has been reduced to 23 deg. C. This has increased the size of the operating window and reduced the number of expensive, and potentially harmful, plant trips. (author)
Incoloy 800 stands up to radiation and corrosion in high temperature gas cooled reactors

International Nuclear Information System (INIS)

Anon.

1975-01-01

Incoloy 800 has been selected for heat exchangers in helium cooled nuclear reactor prototypes for exposure to 350 to 800 0 C helium and high temperature high purity water and steam. 304H stainless steel used in heat exchangers in original design cracked in the superheater area, bellows and tubing after static pressure tests but before exposure to steam. Residual stress, chlorides, and oxygen were deduced to have caused the failures
Differential Top Cross-section Measurements

CERN Document Server

Fenton, Michael James; The ATLAS collaboration

2017-01-01

The top quark is the heaviest known fundamental particle. The measurement of the differential top-quark pair production cross-section provides a stringent test of advanced perturbative QCD calculations. The ATLAS collaboration has performed detailed measurements of those differential cross sections at a centre-of-mass energy of 13 TeV. This talk focuses on differential cross-section measurements in the lepton+jets final state, including using boosted top quarks to probe our understanding of top quark production in the TeV regime.
Prototype Repository. Tracer dilution tests during operation phase, test campaign 3

Energy Technology Data Exchange (ETDEWEB)

Harrstroem, Johan; Andersson, Peter (Geosigma AB (Sweden))

2010-05-15

The Prototype Repository project is focused on testing and demonstrating the function of the SKB deep repository system. The third tracer dilution campaign during the Prototype Repository operation period was performed in January 2010. The purpose was to estimate the groundwater flows and hydraulic gradients in the boreholes vicinity and will function as a reference for comparison with results from modeling and prior assumptions. The test campaign consisted of tracer dilution tests in 13 different borehole sections. Each test consisted of approximately 15-55 min tracer injection time and about 1-3 days dilution test time depending on the transmissivity of the test section. The data interpretation also included estimates of the local hydraulic gradients in the vicinity of the borehole sections
Study on subcooled-forced flow boiling heat transfer and critical heat flux of solid particle-water two-phase mixture

International Nuclear Information System (INIS)

Koizumi, Yasuo; Mochizuki, Manabu; Ohtake, Hiroyasu

1999-01-01

The effect of solid particle introduction on forced flow boiling and the critical heat flux was examined for the mixture of subcooled-water and 0.6 mm glass beads. When the particles were introduced, the growth on of a superheated layer near a wall seemed to be suppressed and the onset of nucleate boiling was delayed. The particles tempted for bubbles to condense at nucleation sites, and then the initiation of net vapor generation was also delayed and sifted to a high wall-superheat region. The nucleate boiling heat transfer was augmented by the particles, which considered to be caused by the combination of the suppression of the superheated layer growth and the promotion of the condensation and dissipation of the bubbles. The wall superheat at the critical heat flux condition was sifted to a high wall superheat region and the critical heat flux itself was also elevated a little. (author)
Coabsorbent and thermal recovery compression heat pumping technologies

CERN Document Server

Staicovici, Mihail-Dan

2014-01-01

This book introduces two of the most exciting heat pumping technologies, the coabsorbent and the thermal recovery (mechanical vapor) compression, characterized by a high potential in primary energy savings and environmental protection. New cycles with potential applications of nontruncated, truncated, hybrid truncated, and multi-effect coabsorbent types are introduced in this work. Thermal-to-work recovery compression (TWRC) is the first of two particular methods explored here, including how superheat is converted into work, which diminishes the compressor work input. In the second method, thermal-to-thermal recovery compression (TTRC), the superheat is converted into useful cooling and/or heating, and added to the cycle output effect via the coabsorbent technology. These and other methods of discharge gas superheat recovery are analyzed for single-, two-, three-, and multi-stage compression cooling and heating, ammonia and ammonia-water cycles, and the effectiveness results are given. The author presen...
Knowledge, attitudes and preferences regarding genetic testing for smoking cessation. A cross-sectional survey among Dutch smokers.

Science.gov (United States)

Quaak, Marieke; Smerecnik, Chris; van Schooten, Frederik J; de Vries, Hein; van Schayck, Constant P

2012-01-01

Objectives Recent research strongly suggests that genetic variation influences smokers' ability to stop. Therefore, the use of (pharmaco) genetic testing may increase cessation rates. This study aims to assess the intention of smokers concerning undergoing genetic testing for smoking cessation and their knowledge, attitudes and preferences about this subject. Design Online cross-sectional survey. Setting Database internet research company of which every inhabitant of the Netherlands of ≥12 years with an email address and capable of understanding Dutch can become a member. Participants 587 of 711 Dutch smokers aged ≥18 years, daily smokers for ≥5 years and smoke on average ≥10 cigarettes/day (response rate=83%). Primary and secondary outcome measures Smokers' knowledge, attitudes and preferences and their intention to undergo genetic testing for smoking cessation. Results Knowledge on the influence of genetic factors in smoking addiction and cessation was found to be low. Smokers underestimated their chances of having a genetic predisposition and the influence of this on smoking cessation. Participants perceived few disadvantages, some advantages and showed moderate self-efficacy towards undergoing a genetic test and dealing with the results. Smokers were mildly interested in receiving information and participating in genetic testing, especially when offered by their general practitioner (GP). Conclusions For successful implementation of genetic testing for smoking in general practice, several issues should be addressed, such as the knowledge on smoking cessation, genetics and genetic testing (including advantages and disadvantages) and the influence of genetics on smoking addiction and cessation. Furthermore, smokers allocate their GPs a crucial role in the provision of information and the delivery of a genetic test for smoking; however, it is unclear whether GPs will be able and willing to take on this role.
Knowledge, attitudes and preferences regarding genetic testing for smoking cessation. A cross-sectional survey among Dutch smokers

Science.gov (United States)

Smerecnik, Chris; van Schooten, Frederik J; de Vries, Hein; van Schayck, Constant P

2012-01-01

Objectives Recent research strongly suggests that genetic variation influences smokers' ability to stop. Therefore, the use of (pharmaco) genetic testing may increase cessation rates. This study aims to assess the intention of smokers concerning undergoing genetic testing for smoking cessation and their knowledge, attitudes and preferences about this subject. Design Online cross-sectional survey. Setting Database internet research company of which every inhabitant of the Netherlands of ≥12 years with an email address and capable of understanding Dutch can become a member. Participants 587 of 711 Dutch smokers aged ≥18 years, daily smokers for ≥5 years and smoke on average ≥10 cigarettes/day (response rate=83%). Primary and secondary outcome measures Smokers' knowledge, attitudes and preferences and their intention to undergo genetic testing for smoking cessation. Results Knowledge on the influence of genetic factors in smoking addiction and cessation was found to be low. Smokers underestimated their chances of having a genetic predisposition and the influence of this on smoking cessation. Participants perceived few disadvantages, some advantages and showed moderate self-efficacy towards undergoing a genetic test and dealing with the results. Smokers were mildly interested in receiving information and participating in genetic testing, especially when offered by their general practitioner (GP). Conclusions For successful implementation of genetic testing for smoking in general practice, several issues should be addressed, such as the knowledge on smoking cessation, genetics and genetic testing (including advantages and disadvantages) and the influence of genetics on smoking addiction and cessation. Furthermore, smokers allocate their GPs a crucial role in the provision of information and the delivery of a genetic test for smoking; however, it is unclear whether GPs will be able and willing to take on this role. PMID:22223839

Experimental study of simulant melt stream-water thermal interaction in pool and narrow geometries

International Nuclear Information System (INIS)

Narayanan, K.S.; Jasmin Sudha, A.; Murthy, S.S.; Rao, E.H.V.M.; Lydia, G.; Das, S.K.; Harvey, J.; Kannan, S.E.

2005-01-01

Full text of publication follows: Small scale experiments were carried out to investigate the thermal interaction characteristics of a few kilograms of Sn Pb, Bi and Zn as hot melt, in the film boiling region of water in an attempt to simulate a coherent fuel coolant interaction during a postulated severe accident in a nuclear reactor. Melt stream solidification and detached debris generation were studied with different melt superheat up to 200 deg. C, at different coolant temperatures of 30 deg. C, 50 deg. C, 70 deg. C, 90 deg. C, in pool geometry and in long narrow coolant column. The material was heated in an Alumina crucible and poured through a hot stainless steel funnel with a nozzle diameter of 7.7 mm, into the coolant. A stainless steel plate was used to collect the solidified mass after the interaction. Temperature monitoring was done in the coolant column close to the melt stream. The melt stream movement inside the coolant was imaged using a video camera at 25 fps. Measured melt stream entry velocity was around 1.5 m/sec. For low melt superheat and low coolant temperature, solidified porous tree like structure extended from the collector plate up to the melt release point. For water temperature of 70 deg. C, the solidified bed height at the center was found to decrease with increase in the melt superheat up to 150 deg. C. Fragmentation was found to occur when the melt superheat exceeded 200 deg. C. Particle size distribution was obtained for the fragmented debris. In 1D geometry, with 50 deg. C superheat, columnar solidification was observed with no fine debris. The paper gives the details of the results obtained in the experiments and highlights the role of Rayleigh-Taylor, Kelvin-Helmholtz instabilities and the melt physical properties on the fragmentation kinetics. (authors)
Wall Correction Model for Wind Tunnels with Open Test Section

DEFF Research Database (Denmark)

Sørensen, Jens Nørkær; Shen, Wen Zhong; Mikkelsen, Robert Flemming

2004-01-01

, the corrections from the model are in very good agreement with the CFD computaions, demonstrating that one-dimensional momentum theory is a reliable way of predicting corrections for wall interference in wind tunnels with closed as well as open cross sections. Keywords: Wind tunnel correction, momentum theory...
Choreographer Pre-Testing Code Analysis and Operational Testing.

Energy Technology Data Exchange (ETDEWEB)

Fritz, David J. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Harrison, Christopher B. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Perr, C. W. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Hurd, Steven A [Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

2014-07-01

Choreographer is a "moving target defense system", designed to protect against attacks aimed at IP addresses without corresponding domain name system (DNS) lookups. It coordinates actions between a DNS server and a Network Address Translation (NAT) device to regularly change which publicly available IP addresses' traffic will be routed to the protected device versus routed to a honeypot. More details about how Choreographer operates can be found in Section 2: Introducing Choreographer. Operational considerations for the successful deployment of Choreographer can be found in Section 3. The Testing & Evaluation (T&E) for Choreographer involved 3 phases: Pre-testing, Code Analysis, and Operational Testing. Pre-testing, described in Section 4, involved installing and configuring an instance of Choreographer and verifying it would operate as expected for a simple use case. Our findings were that it was simple and straightforward to prepare a system for a Choreographer installation as well as configure Choreographer to work in a representative environment. Code Analysis, described in Section 5, consisted of running a static code analyzer (HP Fortify) and conducting dynamic analysis tests using the Valgrind instrumentation framework. Choreographer performed well, such that only a few errors that might possibly be problematic in a given operating situation were identified. Operational Testing, described in Section 6, involved operating Choreographer in a representative environment created through Emulytics^TM . Depending upon the amount of server resources dedicated to Choreographer vis-á-vis the amount of client traffic handled, Choreographer had varying degrees of operational success. In an environment with a poorly resourced Choreographer server and as few as 50-100 clients, Choreographer failed to properly route traffic over half the time. Yet, with a well-resourced server, Choreographer handled over 1000 clients without missrouting. Choreographer
Solidification structure and abrasion resistance of high chromium white irons

Science.gov (United States)

Doğan, Ö. N.; Hawk, J. A.; Laird, G.

1997-06-01

Superior abrasive wear resistance, combined with relatively low production costs, makes high Cr white cast irons (WCIs) particularly attractive for applications in the grinding, milling, and pumping apparatus used to process hard materials. Hypoeutectic, eutectic, and hypereutectic cast iron compositions, containing either 15 or 26 wt pct chromium, were studied with respect to the macrostructural transitions of the castings, solidification paths, and resulting microstructures when poured with varying superheats. Completely equiaxed macrostructures were produced in thick section castings with slightly hypereutectic compositions. High-stress abrasive wear tests were then performed on the various alloys to examine the influence of both macrostructure and microstructure on wear resistance. Results indicated that the alloys with a primarily austenitic matrix had a higher abrasion resistance than similar alloys with a pearlitic/bainitic matrix. Improvement in abrasion resistance was partially attributed to the ability of the austenite to transform to martensite at the wear surface during the abrasion process.
Development of C-band Accelerating Section for SuperKEKB

CERN Document Server

Kamitani, T; Ikeda, M; Kakihara, K; Ohsawa, S; Oogoe, T; Sugimura, T; Takatomi, T; Yamaguchi, S; Yokoyama, K

2004-01-01

For the luminosity upgrade of the present KEK B-factory to SuperKEKB, the injector linac has to increase the positron acceleration energy from 3.5 to 8.0 GeV. In order to double the acceleration field gradient from 21 to 42 MV/m, design studies on C-band accelerator module has started in 2002. First prototype 1-m long accelerating section has been fabricated based upon a design which is half scale of the present S-band section. High power test of the C-band section has been performed at a test stand and later at an accelerator module in the KEKB injector linac. In a beam acceleration test, a field gradient of 41 MV/m is achieved with 43 MW RF power from a klystron. This paper report on the recent status of the high-power test and also the development of a second prototype section.
Evaluation of onset of nucleate boiling models

Energy Technology Data Exchange (ETDEWEB)

Huang, LiDong [Heat Transfer Research, Inc., College Station, TX (United States)], e-mail: lh@htri.net

2009-07-01

This article discusses available models and correlations for predicting the required heat flux or wall superheat for the Onset of Nucleate Boiling (ONB) on plain surfaces. It reviews ONB data in the open literature and discusses the continuing efforts of Heat Transfer Research, Inc. in this area. Our ONB database contains ten individual sources for ten test fluids and a wide range of operating conditions for different geometries, e.g., tube side and shell side flow boiling and falling film evaporation. The article also evaluates literature models and correlations based on the data: no single model in the open literature predicts all data well. The prediction uncertainty is especially higher in vacuum conditions. Surface roughness is another critical criterion in determining which model should be used. However, most models do not directly account for surface roughness, and most investigators do not provide surface roughness information in their published findings. Additional experimental research is needed to improve confidence in predicting the required wall superheats for nucleation boiling for engineering design purposes. (author)
Evaluation of onset of nucleate boiling models

International Nuclear Information System (INIS)

Huang, LiDong

2009-01-01

This article discusses available models and correlations for predicting the required heat flux or wall superheat for the Onset of Nucleate Boiling (ONB) on plain surfaces. It reviews ONB data in the open literature and discusses the continuing efforts of Heat Transfer Research, Inc. in this area. Our ONB database contains ten individual sources for ten test fluids and a wide range of operating conditions for different geometries, e.g., tube side and shell side flow boiling and falling film evaporation. The article also evaluates literature models and correlations based on the data: no single model in the open literature predicts all data well. The prediction uncertainty is especially higher in vacuum conditions. Surface roughness is another critical criterion in determining which model should be used. However, most models do not directly account for surface roughness, and most investigators do not provide surface roughness information in their published findings. Additional experimental research is needed to improve confidence in predicting the required wall superheats for nucleation boiling for engineering design purposes. (author)
Increasing flexibility of coal power plant by control system modifications

Directory of Open Access Journals (Sweden)

Marušić Ante

2016-01-01

Full Text Available Expanding implementation of intermittent renewable energy sources has already started to change the role of thermal power plants in energy systems across Europe. Traditionally base load plants are now forced to operate as peaking plants. A familiar transition in upcoming years is expected in Croatia and coal power plant operators are preparing accordingly. To evaluate cycling capabilities and control system operation for flexible operation of selected 210 MW coal plant, series of tests with different load gradients were performed and results were thoroughly analyzed. Two possible “bottlenecks” are identified, thermal stress in superheater header, and achievable ramping rate considering operational limitations of coal feeders, firing system and evaporator dynamics. Several unexpected readings were observed, usually caused by malfunctioning sensors and equipment, resulting in unexpected oscillations of superheated steam temperature. Based on superheater geometry and experimental data, maximal steam temperature gradient during ramping was evaluated. Since thermal stress was well inside the safety margins, the simulation model of the whole boiler was used to evaluate achievable ramping on electric side.
Factors affecting voluntary HIV counselling and testing among men in Ethiopia: a cross-sectional survey

Directory of Open Access Journals (Sweden)

Leta Tesfaye H

2012-06-01

Full Text Available Abstract Background Voluntary HIV counselling and testing (VCT is one of the key strategies in the HIV/AIDS prevention and control programmes in Ethiopia. However, utilization of this service among adults is very low. The aim of the present study was to investigate factors associated with VCT utilization among adult men since men are less likely than women to be offered and accept routine HIV testing. Methods The study utilized data from the Ethiopian Demographic Health Survey (EDHS 2005, which is a cross-sectional survey conducted on a nationally representative sample. Using cluster sampling, 6,778 men aged 15–59 years were selected from all the eleven administrative regions in Ethiopia. Logistic regression was used to analyze potential factors associated with VCT utilization. Results Overall, 21.9% of urban men and 2.6% of rural men had ever tested for HIV through VCT and most of them had learned their HIV test result. Having no stigmatizing attitudes toward people living with HIV/AIDS was found to be strongly and positively associated with VCT utilization in both urban and rural strata. In rural areas HIV test rates were higher among younger men (aged ≤44 years and those of higher socio-economic position (SEP. Among urban men, risky sexual behaviour was positively associated with VCT utilization whereas being Muslim was found to be inversely associated with utilization of VCT. Area of residence as well as SEP strongly affected men’s level of stigmatizing attitudes toward people living with HIV/AIDS. Conclusions VCT utilization among men in Ethiopia was low and affected by HIV/AIDS-related stigma and residence. In order to increase VCT acceptability, HIV/AIDS prevention and control programs in the country should focus on reducing HIV/AIDS-related stigma. Targeting rural men with low SEP should be given first priority when designing, expanding, and implementing VCT services in the country.
Developing Scientific Reasoning Through Drawing Cross-Sections

Science.gov (United States)

Hannula, K. A.

2012-12-01

Cross-sections and 3D models of subsurface geology are typically based on incomplete information (whether surface geologic mapping, well logs, or geophysical data). Creating and evaluating those models requires spatial and quantitative thinking skills (including penetrative thinking, understanding of horizontality, mental rotation and animation, and scaling). However, evaluating the reasonableness of a cross-section or 3D structural model also requires consideration of multiple possible geometries and geologic histories. Teaching students to create good models requires application of the scientific methods of the geosciences (such as evaluation of multiple hypotheses and combining evidence from multiple techniques). Teaching these critical thinking skills, especially combined with teaching spatial thinking skills, is challenging. My Structural Geology and Advanced Structural Geology courses have taken two different approaches to developing both the abilities to visualize and to test multiple models. In the final project in Structural Geology (a 3rd year course with a pre-requisite sophomore mapping course), students create a viable cross-section across part of the Wyoming thrust belt by hand, based on a published 1:62,500 geologic map. The cross-section must meet a number of geometric criteria (such as the template constraint), but is not required to balance. Each student tries many potential geometries while trying to find a viable solution. In most cases, the students don't visualize the implications of the geometries that they try, but have to draw them and then erase their work if it does not meet the criteria for validity. The Advanced Structural Geology course used Midland Valley's Move suite to test the cross-sections that they made in Structural Geology, mostly using the flexural slip unfolding algorithm and testing whether the resulting line lengths balanced. In both exercises, students seemed more confident in the quality of their cross-sections when the
Statistical test of reproducibility and operator variance in thin-section modal analysis of textures and phenocrysts in the Topopah Spring member, drill hole USW VH-2, Crater Flat, Nye County, Nevada

International Nuclear Information System (INIS)

Moore, L.M.; Byers, F.M. Jr.; Broxton, D.E.

1989-06-01

A thin-section operator-variance test was given to the 2 junior authors, petrographers, by the senior author, a statistician, using 16 thin sections cut from core plugs drilled by the US Geological Survey from drill hole USW VH-2 standard (HCQ) drill core. The thin sections are samples of Topopah Spring devitrified rhyolite tuff from four textural zones, in ascending order: (1) lower nonlithophysal, (2) lower lithopysal, (3) middle nonlithophysal, and (4) upper lithophysal. Drill hole USW-VH-2 is near the center of the Crater Flat, about 6 miles WSW of the Yucca Mountain in Exploration Block. The original thin-section labels were opaqued out with removable enamel and renumbered with alpha-numeric labels. The sliders were then given to the petrographer operators for quantitative thin-section modal (point-count) analysis of cryptocrystalline, spherulitic, granophyric, and void textures, as well as phenocryst minerals. Between operator variance was tested by giving the two petrographers the same slide, and within-operator variance was tested by the same operator the same slide to count in a second test set, administered at least three months after the first set. Both operators were unaware that they were receiving the same slide to recount. 14 figs., 6 tabs
cmpXLatt: Westinghouse automated testing tool for nodal cross section models

International Nuclear Information System (INIS)

Guimaraes, Petri Forslund; Rönnberg, Kristian

2011-01-01

The procedure for evaluating the merits of different nodal cross section representation models is normally both cumbersome and time consuming, and includes many manual steps when preparing appropriate benchmark problems. Therefore, a computer tool called cmpXLatt has been developed at Westinghouse in order to facilitate the process of performing comparisons between nodal diffusion theory results and corresponding transport theory results on a single node basis. Due to the large number of state points that can be evaluated by cmpXLatt, a systematic and comprehensive way of performing verification and validation of nodal cross section models is provided. This paper presents the main features of cmpXLatt and demonstrates the benefits of using cmpXLatt in a real life application. (author)
Experimental investigation of cooling by top spray and bottom flooding of a simulated 64 rod bundle for a BWR. Pt. 2. Main experiment with modified test section

International Nuclear Information System (INIS)

Nilsson, L.; Gustafson, L.; Harju, R.

1978-06-01

The cooling of an electrically heated, full scale 64-rod bundle has been investigated under simulated emergency core cooling conditions. Emphasis was laid on measurements of rod cladding and canister temperatures. By means of difference pressure measurements the levels in bundle, by-pass and downcomer could be estimated and thus the effective reflooding velocity. The test section was modified compared to the pre-tests, in order to improve system effects simulation. A new rod bundle was installed including a hollow, water, rod and 63 indirectly heated rods. Parameter effects of coolant mass flow rate and distribution, initial cladding temperature, pressure and power were studied. The effect of the way the test section was vented was also investigated and turned out to be very significant. (author)
Release of Corrosive Species above the Grate in a Waste Boiler and the Implication for Improved Electrical Efficiency

DEFF Research Database (Denmark)

Bøjer, Martin; Jensen, Peter Arendt; Dam-Johansen, Kim

2010-01-01

A relatively low electrical efficiency of 20−25% is obtained in typical west European waste boilers. Ash species released from the grate combustion zone form boiler deposits with high concentrations of Cl, Na, K, Zn, Pb, and S that cause corrosion of superheater tubes at high temperature....... The superheater steam temperature has to be limited to around 425 °C, and thereby, the electrical efficiency remains low compared to wood or coal-fired boilers. If a separate part of the flue gas from the grate has a low content of corrosive species, it may be used to superheat steam to a higher temperature......, and thereby, the electrical efficiency of the plant can be increased. In this study, the local temperature, the gas concentrations of CO, CO2, and O2, and the release of the volatile elements Cl, S, Na, K, Pb, Zn, Cu, and Sn were measured above the grate in a waste boiler to investigate if a selected fraction...
Prevalence of prior HIV testing and associated factors among MSM in Zhejiang Province, China: a cross-sectional study

Directory of Open Access Journals (Sweden)

Runhua Li

2016-11-01

Full Text Available Abstract Background Men who have sex with men (MSM have become one of high-risk population for human immunodeficiency virus (HIV infection, due to their multiple sex partners and unprotected anal intercourse. Promoting HIV testing is an effective strategy for the prevention and control of HIV infection. We assessed the factors associated with a prior HIV testing history, which could provide guidance for implementation of future HIV intervention programs. Methods A cross-sectional study was conducted in three cities of Zhejiang Province, namely, Hangzhou, Ningbo and Wenzhou, using respondent-driven sampling, between December 2013 and June 2014. A face-to-face questionnaire survey was employed to collect relevant information about HIV testing. Univariate and multivariate logistic regression analyses were used to identify the factors associated with a prior HIV testing history. Results The adjusted rate of prior HIV testing among MSM in Zhejiang Province was 55.9 %. The adjusted rates of HIV and syphilis infections among MSM in Zhejiang Province were 14.0 % and 11.4 %, respectively. A weighted multivariate analysis showed that MSM of older age were more likely to be tested, as were MSM with higher level of education, self-reported homosexuality and a higher frequency of receiving AIDS/sexually transmitted infections educational intervention in the past year. MSM with suicidal inclination and self-perceived lower possibility of HIV infection were less likely to report ever having undergone an HIV test. Conclusions The prevalence of prior HIV testing among MSM in Zhejiang Province, China is low. Effective and more frequent interventional measures should be adopted to improve risk awareness and psychosocial support for younger, less educated MSM, and to encourage more MSM to undergo HIV testing.
A pilot application of the RELAP file to the steady state and transient analysis of a test section inside the BR2 reactor

International Nuclear Information System (INIS)

Ferri, M. G.; D'Auria, F.; Forasassi, G.; Giot, M.

2000-01-01

BR2 is a material test reactor sited in the Belgian Nuclear Research Centre in Mol. The main research programs carried out in BR2 are related to the safety of nuclear reactor structural materials and fuels, in normal and accidental conditions, plant lifetime evaluation and ageing of components. In this framework, a computer program that allows the performance of detailed, steady state analysis of several kinds of in-pile sections with an axisymmetrical geometry has been developed. Furthermore, comparing its results with those of the well known, extensively used, Relap5/Mod 3.2 code on a test problem has validated this program. This was performed in three steps: 1. modalisation development of a subsystem of a typical in-pile section. 2. steady state analysis and comparison with the above-mentioned program. 3. transient simulation of the same system; the considered transient consists of a loss of coolant flow. (author)
Studying the processes of sodium-water interaction in the BOR-60 reactor micromodule steam generator

International Nuclear Information System (INIS)

Tsykanov, V.A.; Antipin, G.K.; Borisov, V.V.

1981-01-01

Main results of experimental studies of emergency regimes of micromodule steam generator (MSG) at small and big leaks of water into sodium, realized using the 30 MW MSG, operating in the BOR-o0 reactor, are considered. The aims of the study are as follows: the modelling of macroleak in ''Nadja'' steam generator for the BN-350 reactor; testing the conceptions of alarm signalling and MSG protection; testing under real conditions of new perspective systems of leak detection; gaining the experimence and development of the ways to eliminate the consequences of accident caused by big water leak into sodium; accumulation of knowledge on restoration of MSG operating ability after accident; experimental test of calculational techniques for big leak accidents to use them in future for calculational studies of similar situations at other reactors equipped with sodium-water steam generators; refinement of characteristics of hydrodynamic and thermal effects interaction zone for big leak in real circuit during the plant operation. A series of experiments with the imitation of water leak into sodium by means of argon and steam supply through injection devices, located before the steam superheater module of one of the sections and between evaporator module of the same section, is conducted. The range of steam flow rate is 0.02-0.45 g/s. Duration of steam supply is 100-400 s. A conclusion is made that the results obtained can be used for steam generator of the BN-350 reactor [ru
NASA Hybrid Wing Aircraft Aeroacoustic Test Documentation Report

Science.gov (United States)

Heath, Stephanie L.; Brooks, Thomas F.; Hutcheson, Florence V.; Doty, Michael J.; Bahr, Christopher J.; Hoad, Danny; Becker, Lawrence; Humphreys, William M.; Burley, Casey L.; Stead, Dan;

2016-01-01

This report summarizes results of the Hybrid Wing Body (HWB) N2A-EXTE model aeroacoustic test. The N2A-EXTE model was tested in the NASA Langley 14- by 22-Foot Subsonic Tunnel (14x22 Tunnel) from September 12, 2012 until January 28, 2013 and was designated as test T598. This document contains the following main sections: Section 1 - Introduction, Section 2 - Main Personnel, Section 3 - Test Equipment, Section 4 - Data Acquisition Systems, Section 5 - Instrumentation and Calibration, Section 6 - Test Matrix, Section 7 - Data Processing, and Section 8 - Summary. Due to the amount of material to be documented, this HWB test documentation report does not cover analysis of acquired data, which is to be presented separately by the principal investigators. Also, no attempt was made to include preliminary risk reduction tests (such as Broadband Engine Noise Simulator and Compact Jet Engine Simulator characterization tests, shielding measurement technique studies, and speaker calibration method studies), which were performed in support of this HWB test. Separate reports containing these preliminary tests are referenced where applicable.

Commissioning of the STAR test section for experimental simulation of loss of coolant accident using the EC-208 instrumented fuel assembly of the IEA-R1 reactor

Energy Technology Data Exchange (ETDEWEB)

Maprelian, Eduardo; Torres, Walmir M.; Prado, Adelk C.; Umbehaun, Pedro E.; Franca, Renato L.; Santos, Samuel C.; Macedo, Luiz A.; Sabundjian, Gaiane, E-mail: emaprel@ipen.br, E-mail: wmtorres@ipen.br, E-mail: acprado@ipen.br, E-mail: umbehaun@ipen.br, E-mail: rlfranca@ipen.br, E-mail: samuelcs@ipen.br, E-mail: lamacedo@ipen.br, E-mail: gdjian@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SO (Brazil)

2015-07-01

The three basic safety functions of Research Reactors (RR) are the safe shutdown of the reactor, the proper cooling of the decay heat of the fuel elements and the confinement of radioactive materials. Compared to Nuclear Power Reactors, RR power release is small, yet its three safety functions must be met to ensure the integrity of the reactor. During a loss of coolant accident (LOCA) in pool type RR, partial or complete loss of pool water may occur, with consequent partial or complete uncovering of the fuel assemblies. In such an accident, the decay heat removal safety function must not be compromised. The Test Section for Experimental Simulation of Loss of Coolant Accident (STAR) is in commissioning phase. This test section will provide experimental data on partial and total uncovering of the EC-208 instrumented fuel assembly (IFA) irradiated in the IEA-R1. Experimental results will be useful in validation of computer codes for RR safety analysis, particularly on heat removal efficiency aspects (safety function) in accident conditions. STAR comprises a base on which is installed the IFA, the cylindrical stainless steel hull, the compressed air system for the test section emptying and refilling, and the instrumentation for temperature and level measurements. The commissioning tests or pre-operational check, consist of several preliminary tests to verify experimental procedures, the difficulties during assembling of STAR in the pool, the difficulties in control the emptying and refilling velocities, as well as, the repeatability capacity, tests of equipment, valves and systems and tests of instrumentation and data acquisition system. Safety, accuracy and easiness of operation will be checked. (author)
Measurement of the cross-section of electron-positron scattering at high energy and quantum electrodynamics testing

International Nuclear Information System (INIS)

Lalanne, D.

1970-01-01

The experiment we have performed on the ACO (Orsay Collider Ring) is one of the most accurate tests of quantum electrodynamics over very short interaction distances (10 -14 cm). We have studied the electron-positron elastic scattering at very wide angle. This work is divided into 4 parts. The first part reviews recent tests of quantum electrodynamics and presents the electron-positron elastic scattering. The second part describes the measurement of brightness: the experimental device, data analysis and accuracy. The measurement of brightness has been performed by detecting the photons emitted in the double Bremsstrahlung reaction: e + e - → e + e - γγ. The third part deals with the measurement of the number of Bhabha events. The last part compares the experimental value of the Bhabha scattering with the theoretically expected value. We have got the following results: the number of Bhabha events: 757 events, the experimental value for Bhabha scattering cross-section: [1.97 ± 0.09 (stat.) ± 0.10 (syst.)]*10 -31 cm 2 . The comparison of this experimental value with the expected value has allowed us to set the lower limit of the cutting parameter Λ: Λ > 2 GeV

Structural fatigue test results for large wind turbine blade sections

Science.gov (United States)

Faddoul, J. R.; Sullivan, T. L.

1982-01-01

In order to provide quantitative information on the operating life capabilities of wind turbine rotor blade concepts for root-end load transfer, a series of cantilever beam fatigue tests was conducted. Fatigue tests were conducted on a laminated wood blade with bonded steel studs, a low cost steel spar (utility pole) with a welded flange, a utility pole with additional root-end thickness provided by a swaged collar, fiberglass spars with both bonded and nonbonded fittings, and, finally, an aluminum blade with a bolted steel fitting (Lockheed Mod-0 blade). Photographs, data, and conclusions for each of these tests are presented. In addition, the aluminum blade test results are compared to field failure information; these results provide evidence that the cantilever beam type of fatigue test is a satisfactory method for obtaining qualitative data on blade life expectancy and for identifying structurally underdesigned areas (hot spots).
Adhesion Strength of Biomass Ash Deposits

DEFF Research Database (Denmark)

Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

2015-01-01

This study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000°C. Subsequently, the deposits were sheared off with the help of an electrically...... controlled arm. Higher sintering temperatures resulted in greater adhesion strengths, with a sharp increase observed near the melting point of the ash. Repetition of experiments with fixed operation conditions revealed considerable variation in the obtained adhesion strengths, portraying the stochastic...
Integral test of neutron cross section data for future reactor materials through measurement and analysis of neutron spectra

International Nuclear Information System (INIS)

Mori, Takamasa

1985-05-01

In order to assess the cross section data for future reactor materials, such as molybdenum, niobium, titanium, lithium and fluorine, the angular neutron spectra in test piles of these materials or their chemical compounds have been measured in the energy range from a few keV to a few MeV by the linac time-of-flight method. The results have been compared with those theoretically calculated from the evaluated cross section data in such as JENDL-2 (or JENDL-1, JENDL-3PR1) and ENDF/B-IV. For both of molybdenum and niobium, it has been found that the energy distribution of inelastically scattered neutrons plays an important role in the analysis, and the JENDL library gives better predictions of spectrum shapes than ENDF/B-IV for both cases. In the case of niobium, however, it appears that the values of inelastic scattering cross section in JENDL-2 are too small around 2 MeV. It has been also found for niobium that the cross section data below 100 keV in ENDF/B-IV are inadequate. In a titanium pile, a discrepancy between the measured spectrum and the calculated one from ENDF/B-IV has been found in the energy range from about 60 keV to a few 100 keV. In order to investigate the cause of this discrepancy, the total cross sections for titanium have been measured by the transmission method. In the case of lithium, the discrepancy between the measured and calculated spectra is considerably reduced by adopting the angular distribution for 7 Li from ENDF/B-IV above about 500 keV. In the case of fluorine, spatial distributions of neutrons and X-rays have been also measured in both piles by the activation method to estimate the influence of photoneutrons generated in the sample material on the neutron distribution, and it has been found that their influence below 1 MeV is not so large as is necessary to be taken into account for the present assessment. (J.P.N)
Materials for higher steam temperatures (up to 600 deg C) in biomass and waste fired plant. A review of present knowledge; Material foer hoegre aangtemperaturer (upp till 600 grader C) i bio- och avfallseldade anlaeggningar

Energy Technology Data Exchange (ETDEWEB)

Staalenheim, Annika; Henderson, Pamela

2011-02-15

A goal for the Swedish power industry is to build a demonstration biomass-fired plant with 600 deg C steam data in 2015. Vaermeforsk also has a goal to identify materials that can be used in such a plant. This project involves a survey of present knowledge and published articles concerning materials that are suitable for use in biomass and wastefired plants with steam data up to 600 deg C. The information has been gathered from plants presently in operation, and from field tests previously performed with probes. Plants firing only household waste are excluded. The components considered are waterwalls/furnace walls (affected because of higher steam pressures) and superheaters. Fireside corrosion and steam-side oxidation are dealt with. Candidate materials (or coatings) are suggested and areas for further research have been identified. The purpose of this project is to give state-of-the-art information on what materials could be used in biomass and waste-fired plant to reach a maximum steam temperature of 600 deg C. This report is aimed at suppliers of boilers and materials, energy utility companies and others involved in building new plant with higher steam data. In accordance with the goals of this project: - Materials suitable for use at higher steam temperatures (up to 600 deg C steam) in wood-based biomass and waste-fired plant have been identified. Austenitic stainless steels HR3C, TP 347 HFG and AC66 all have adequate strength, steam-side oxidation and fireside corrosion resistance for use as superheaters. AC66 and HR3C have better steam-side oxidation resistance than TP 347 HFG , but TP 347 HFG has better fireside corrosion resistance. It is recommended that TP 347 HFG be shot-peened on the inside to improve the oxidation resistance if in service with steam temperatures above 580 deg C. - Furnace walls coated with Ni-based alloys or a mixture of Ni- alloy and ceramic show good corrosion resistance at lower temperatures and should be evaluated at higher
Rank-based testing of equal survivorship based on cross-sectional survival data with or without prospective follow-up.

Science.gov (United States)

Chan, Kwun Chuen Gary; Qin, Jing

2015-10-01

Existing linear rank statistics cannot be applied to cross-sectional survival data without follow-up since all subjects are essentially censored. However, partial survival information are available from backward recurrence times and are frequently collected from health surveys without prospective follow-up. Under length-biased sampling, a class of linear rank statistics is proposed based only on backward recurrence times without any prospective follow-up. When follow-up data are available, the proposed rank statistic and a conventional rank statistic that utilizes follow-up information from the same sample are shown to be asymptotically independent. We discuss four ways to combine these two statistics when follow-up is present. Simulations show that all combined statistics have substantially improved power compared with conventional rank statistics, and a Mantel-Haenszel test performed the best among the proposal statistics. The method is applied to a cross-sectional health survey without follow-up and a study of Alzheimer's disease with prospective follow-up. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Energy-efficiency-oriented cascade control for vapor compression refrigeration cycle systems

International Nuclear Information System (INIS)

Yin, Xiaohong; Wang, Xinli; Li, Shaoyuan; Cai, Wenjian

2016-01-01

The vapor compression refrigeration cycle (VCC) system plays an important role and accounts for a large proportion of energy consumption from the heating, ventilating, and air-conditioning (HVAC) system. The traditional control approaches, for example PID control method, however, cannot meet the cooling demands with the satisfactory energy efficiency as well. This paper presents a novel energy-efficiency-oriented cascade control strategy for the VCC systems to improve the energy efficiency and fulfill the cooling requirements of indoor occupants simultaneously. In outer loop, a mathematic model is developed to determine the set point of superheat by a PI controller based on the nonlinear correlation between cooling demands and superheat degree. In inner loop, the pressure difference and superheat degree of evaporator are controlled by a model predictive control (MPC) strategy to track the values which are determined in the outer loop, simultaneously to enhance system efficiency of the VCC systems. Simulation and experiments studies are carried out to show the effectiveness of this proposed cascade control strategy and the results indicate significant tracking performance and energy efficiency improvements on VCC system. Compared to other schemes, the proposed cascade control strategy can improve energy efficiency by up to 5.8%. - Highlights: • Energy-efficiency-oriented cascade control strategy for VCC system is presented. • The correlation between cooling requirements and superheat is analyzed. • A MPC-based controller is developed to maximize system energy efficiency. • Experimental results confirm the effectiveness of the proposed control strategy.
Augmented cross-sectional studies with abbreviated follow-up for estimating HIV incidence.

Science.gov (United States)

Claggett, B; Lagakos, S W; Wang, R

2012-03-01

Cross-sectional HIV incidence estimation based on a sensitive and less-sensitive test offers great advantages over the traditional cohort study. However, its use has been limited due to concerns about the false negative rate of the less-sensitive test, reflecting the phenomenon that some subjects may remain negative permanently on the less-sensitive test. Wang and Lagakos (2010, Biometrics 66, 864-874) propose an augmented cross-sectional design that provides one way to estimate the size of the infected population who remain negative permanently and subsequently incorporate this information in the cross-sectional incidence estimator. In an augmented cross-sectional study, subjects who test negative on the less-sensitive test in the cross-sectional survey are followed forward for transition into the nonrecent state, at which time they would test positive on the less-sensitive test. However, considerable uncertainty exists regarding the appropriate length of follow-up and the size of the infected population who remain nonreactive permanently to the less-sensitive test. In this article, we assess the impact of varying follow-up time on the resulting incidence estimators from an augmented cross-sectional study, evaluate the robustness of cross-sectional estimators to assumptions about the existence and the size of the subpopulation who will remain negative permanently, and propose a new estimator based on abbreviated follow-up time (AF). Compared to the original estimator from an augmented cross-sectional study, the AF estimator allows shorter follow-up time and does not require estimation of the mean window period, defined as the average time between detectability of HIV infection with the sensitive and less-sensitive tests. It is shown to perform well in a wide range of settings. We discuss when the AF estimator would be expected to perform well and offer design considerations for an augmented cross-sectional study with abbreviated follow-up. © 2011, The
Comparison of constant-rate pumping test and slug interference test results at the Hanford Site B pond multilevel test facility

International Nuclear Information System (INIS)

Spane, F.A. Jr.; Thorne, P.D.

1995-10-01

Pacific Northwest Laboratory (PNL), as part of the Hanford Site Ground-Water Surveillance Project, is responsible for monitoring the movement and fate of contamination within the unconfined aquifer to ensure that public health and the environment are protected. To support the monitoring and assessment of contamination migration on the Hanford Site, a sitewide 3-dimensional groundwater flow model is being developed. Providing quantitative hydrologic property data is instrumental in development of the 3-dimensional model. Multilevel monitoring facilities have been installed to provide detailed, vertically distributed hydrologic characterization information for the Hanford Site unconfined aquifer. In previous reports, vertically distributed water-level and hydrochemical data obtained over time from these multi-level monitoring facilities have been evaluated and reported. This report describes the B pond facility in Section 2.0. It also provides analysis results for a constant-rate pumping test (Section 3.0) and slug interference test (Section 4.0) that were conducted at a multilevel test facility located near B Pond (see Figure 1. 1) in the central part of the Hanford Site. A hydraulic test summary (Section 5.0) that focuses on the comparison of hydraulic property estimates obtained using the two test methods is also presented. Reference materials are listed in Section 6.0
Effect of foot placements during sit to stand transition on timed up and go test in stroke subjects: A cross sectional study.

Science.gov (United States)

Joshua, Abraham M; Karnad, Shreekanth D; Nayak, Akshatha; Suresh, B V; Mithra, Prasanna; Unnikrishnan, B

2017-01-01

Timed up and go (TUG) test is been used as a screening tool for the assessment of risk of falling in individuals following stroke. Though TUG test is a quick test, it has fair sensitivity compared to other tests. This study was carried out to obtain and compare test scores for different types of foot placements during sit to stand transition in stroke subjects. A Cross-sectional study with purposive sampling included 28 post stroke subjects who were able to walk 6 meter with or without assistance. Timed Up and Go test was carried out with four different types of foot placements and scores were recorded. The data were compared using Kruskal-Wallis One way analysis of variance and Wilcoxon signed ranks test. There were comparable differences between asymmetric 1 test strategy which involved affected extremity to be placed behind the unaffected and other test strategies (Z = -4.457,-3.848,-4.458; p = 0.000). The initial foot placements during sit to stand transition influenced the time taken to complete the test which was significantly higher in asymmetric 1 strategy, Incorporation of the initial foot placement mainly asymmetric 1 strategy into conventional TUG test would help in identifying accurately the subject's functional mobility and postural stability.
Deposit Shedding in Biomass-fired Boilers: Shear Adhesion Strength Measurements

DEFF Research Database (Denmark)

Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

2016-01-01

. Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared...... on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, deposit composition, sintering duration, and steel type...... on the adhesion strength....
Nuclear power plant

International Nuclear Information System (INIS)

Orlov, V.V.; Rineisky, A.A.

1975-01-01

The invention is aimed at designing a nuclear power plant with a heat transfer system which permits an accelerated fuel regeneration maintaining relatively high initial steam values and efficiency of the steam power circuit. In case of a plant with three circuits the secondary cooling circuit includes a steam generator with preheater, evaporator, steam superheater and intermediate steam superheater. At the heat supply side the latter is connected with its inlet to the outlet of the evaporator and with its outlet to the low-temperature side of the secondary circuit
Effect of Chlorine and Sulphur on Stainless Steel (AISI 310) Due To High Temperature Corrosion.

OpenAIRE

Onaivi Daniel Azamata; Titus Yusuf Jibatswen; Odinize C. Michael

2016-01-01

In a power station boiler, there are temperature of regimes of corrosion which occurs mainly in the economizer, boiler steam generation tubes, super-heater tubes and air tubes. The specific gas temperatures in degrees centigrade for the following include: 150 – 370oC for the economizer, 1000 – 1650oC for the boiler steam generation tubes, 650 – 1000oC for super-heater tubes and 1000 – 1200oC for air tubes. For power station boilers that burn coal as the source of fuel it is recommended that a...
Steam generator arrangement

International Nuclear Information System (INIS)

Ssinegurski, E.

1981-01-01

A steam flow path arrangement for covering the walls of the rear gas pass of a steam generator is disclosed. The entire flow passes down the sidewalls with a minor portion then passing up through the rear wall to a superheater inlet header at an intermediate elevation. The major portion of the flow passes up the front wall and through hanger tubes to a roof header. From there the major portion passes across the roof and down the rear wall to the superheater inlet header at the intermediate elevation
Factors associated with continuing emergence of β-thalassemia major despite prenatal testing: a cross-sectional survey

Directory of Open Access Journals (Sweden)

Al Sabbah H

2017-09-01

Full Text Available Haleama Al Sabbah,1 Sarah Khan,1 Abdallah Hamadna,2 Lamia Abu Ghazaleh,2 Anwar Dudin,2 Bashar Adnan Karmi3 1College of Natural and Health Sciences, Zayed University, Dubai, UAE; 2Faculty of Medicine, An-Najah National University, Nablus, Palestine; 3Thalassemia Patients’ Friends Society, Ramallah, Palestine Purpose: Health care initiatives focusing on prenatal testing and premarital genetic screening aiming to reduce the incidence of β-thalassemia have emerged during the last decade. In Palestine, 4% of the population are known thalassemia carriers with new cases continuing to appear despite the availability of prenatal testing. This study aims to identify factors that influence the decision to retain or abort fetuses affected by β-thalassemia in Palestine. Methods: Convenience sampling was used to select 32 women (72 fetuses who were at risk of having a baby with β-thalassemia. A questionnaire on prenatal testing, test results, pregnancy outcomes, and factors influencing the decision to terminate the pregnancy were used for this cross-sectional study. The data were analyzed using SPSS version 17. Results: Among the fetuses screened, 36 (50% were thalassemia carriers and 20 (28% had β-thalassemia; 17 (85% affected fetuses were aborted. Religious beliefs were the most cited reason for opposing abortion while prior experience with β-thalassemia patients and awareness programs promoted abortions. Mothers who opted to retain an affected fetus had modest educational attainment. Higher educational level was significantly associated with the decision to abort an affected fetus (p<0.05. Conclusion: A religious consensus is needed on the abortion of fetuses affected by β-thalassemia. Improving female education and increasing awareness on thalassemia could help reduce the incidence of β-thalassemia in Palestine and around the world. Keywords: abortion, Islam, fetus, awareness
Design heating test section HeaTiNG-02

International Nuclear Information System (INIS)

Riswan Djambiar; Sagino; Dedy Haryanto; Joko Prasetio Witoko

2013-01-01

HeaTiNG-02 is a component test loop BETA which serves as a heater in conducting experimental heat transfer processes in two-phase flow in narrow slit-shaped plate, considering this phenomenon is one of the conditions postulated accident scenarios a NPP type PWR. To produce heat for the heating component takes the AC power the source voltage can be set from 0 Volts to 220 Volts with no more than a maximum power of 25 KVA. To obtain the thermal conditions on HeaTiNG-02 heating wire dimensions need to be determined and the corresponding voltage so that it will an expected power. Determination of the dimensions of the heater wire through calculations using electricity formulations. Retrieved draft heater test BETA (UUB) HeaTiNG-02 use material super kanthal (FeCuAl) in diameter (Ø) = 2 mm and wire length 3770 mm. Voltage regulators with a maximum power of 25 kVA with a minimum voltage of 0 volts and a maximum of 220 volts. Heater is used as the base to form refractory stone trench. (author)
Ice-condenser aerosol tests

International Nuclear Information System (INIS)

Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K.

1991-09-01

This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between ∼0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m 3 /s resulted in stable thermal stratification whereas flows less than 0.1 m 3 /s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs
Operational test report for LERF Basin 242AL-44 integrity test

International Nuclear Information System (INIS)

Galioto, T.M.

1994-01-01

This operational test report documents the results of LERF operational testing per operational test procedure (OTP) TFPE-WP-0231, ''LERF Basin Integrity Testing.'' The primary purpose of the OTP was to resolve test exceptions generated as a result of TFPE-WP-0184. The TOP was prepared and performed in accordance with WHC-SD-534-OTP-002, ''Operational Test Plan for the 242-A Evaporator Upgrades and the Liquid Effluent Retention Facility.'' WHC-S-086, ''Specification for Operational Testing of the Liquid Effluent Retention Facility, Basin Integrity Testing,'' identified the test requirements and acceptance criteria. The completed, signed-off test procedure is contained in Appendix A. The test log is contained in Appendix B. Section 2.1 describes all the test exceptions written during performance of the Operational Test Procedure. The test revisions generated during the testing are discussed in Section 2.2. The dispositioned test exception forms are contained in Appendix C
Properties and Microstructure of Laser Welded VM12-SHC Steel Pipes Joints

Directory of Open Access Journals (Sweden)

Skrzypczyk A.

2016-06-01

Full Text Available Paper presents results of microstructure and tests of welded joints of new generation VM12-SHC martensitic steel using high power CO2 laser (LBW method with bifocal welding head. VM12-SHC is dedicated to energetic installation material, designed to replace currently used. High content of chromium and others alloying elements improve its resistance and strength characteristic. Use of VM12-SHC steel for production of the superheaters, heating chambers and walls in steam boilers resulted in various weldability researches. In article are presented results of destructive and non-destructive tests. For destructive: static bending and Vickers hardness tests, and for non-destructive: VT, RT, UT, micro and macroscopic tests were performed.
Convective boiling in a parallel microchannel heat sink with a diverging cross-section design and artificial nucleation sites

International Nuclear Information System (INIS)

Lu, Chun Ting; Pan, Chin

2009-01-01

To develop a highly stable boiling heat transfer microchannel heat sink, the three types of diverging microchannels, namely Type-1, Type-2 and Type-3, were designed to explore experimentally the effect of different distribution of artificial nucleation sites on enhancing boiling heat transfer in 10 parallel diverging microchannels with a mean hydraulic diameter of 120 μm. The Type-1 system is with no cavities, Type-2 is with cavities distributed uniformly along the downstream half of the channel, while Type-3 is with cavities distributed uniformly along the whole channel. The artificial nucleation sites are laser-etched pits on the channel bottom wall with a mouth diameter of about 20-22 μm based on the heterogeneous nucleation theory. The results of the present study reveal the presence of the artificial nucleation sites for flow boiling in parallel diverging microchannel significantly reduces the wall superheat and enhances the boiling heat transfer performance. Additionally, the Type-3 design demonstrates the best boiling heat transfer performance. (author)
Wall correction model for wind tunnels with open test section

DEFF Research Database (Denmark)

Sørensen, Jens Nørkær; Shen, Wen Zhong; Mikkelsen, Robert Flemming

2006-01-01

In the paper we present a correction model for wall interference on rotors of wind turbines or propellers in wind tunnels. The model, which is based on a one-dimensional momentum approach, is validated against results from CFD computations using a generalized actuator disc principle. In the model...... good agreement with the CFD computations, demonstrating that one-dimensional momentum theory is a reliable way of predicting corrections for wall interference in wind tunnels with closed as well as open cross sections....

The diagnostic performance evaluation of the SD BIOLINE HIV/syphilis Duo rapid test in southern Ethiopia: a cross-sectional study.

Science.gov (United States)

Shimelis, Techalew; Tadesse, Endale

2015-04-23

To determine the diagnostic performance of the SD BIOLINE HIV/syphilis Duo rapid test. A hospital-based cross-sectional study. This evaluation was conducted at one of the largest hospitals in southern Ethiopia. Serum samples obtained from clients attending the antiretroviral therapy and voluntary counselling and testing centres were used. Sera were originally collected for the purpose of investigating syphilis epidemiology. The performance of the test to detect HIV was evaluated using 400 sera (200 HIV positives and 200 HIV negatives). Also, its performance to detect syphilis was evaluated using 85 syphilis positive and 100 syphilis negative serum samples. Individuals tiebreaker to determine the result. We also used ELISA to resolve discordant HIV results. Syphilis serostatus was determined using the Treponema pallidum haemagglutination assay (TPHA). The respective sensitivity, specificity, positive predictive value and negative predictive value of the SD BIOLINE HIV/syphilis Duo test were 100, 99.5, 99.5 and 100% for HIV and 97.6, 96, 95.4 and 98% for syphilis testing, respectively. In reference to TPHA, the test kit reported 4 false positives and 2 false negative results for syphilis. The κ values were 0.99 for HIV testing and 0.94 for syphilis testing. The excellent performance of the SD BIOLINE HIV/syphilis Duo test to detect HIV as well as syphilis facilitates the integration of syphilis testing and treatment to the already established HIV prevention programme, ultimately contributing to the dual HIV and syphilis elimination goal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
A cross-sectional survey of attitudes to HIV risk and rapid HIV testing among clients of sex workers in Switzerland.

Science.gov (United States)

Darling, Katharine E A; Diserens, Esther-Amélie; N'garambe, Chantal; Ansermet-Pagot, Anne; Masserey, Eric; Cavassini, Matthias; Bodenmann, Patrick

2012-10-01

To assess attitudes to HIV risk and acceptability of rapid HIV testing among clients of street-based female sex workers (FSW) in Lausanne, Switzerland, where HIV prevalence in the general population is 0.4%. The authors conducted a cross-sectional study in the red light district of Lausanne for five nights in September of 2008, 2009 and 2010. Clients of FSW were invited to complete a questionnaire in the street assessing demographic characteristics, attitudes to HIV risk and HIV testing history. All clients interviewed were then offered anonymous finger stick rapid HIV testing in a van parked on-site. The authors interviewed 112, 127 and 79 clients in 2008, 2009 and 2010, respectively. All were men, average age 32-37 years old; 40-60% were in a stable relationship. History of unprotected sex was higher with non-commercial partners (33-50%) than with FSW (6-11%); 29-46% of clients had never undergone an HIV test. Anonymous rapid HIV testing was accepted by 45-50% of clients. Out of 109 HIV tests conducted during the three study periods, none was reactive. On-site HIV counselling and testing is acceptable among clients of FSW in this urban setting. These individuals represent an unquantified population, a proportion of which has an incomplete understanding of HIV risk in the face of high-risk behaviour, with implications for potential onward transmission to non-commercial sexual partners.
HIV testing and burden of HIV infection in black cancer patients in Johannesburg, South Africa: a cross-sectional study.

Science.gov (United States)

Sengayi, Mazvita; Babb, Chantal; Egger, Matthias; Urban, Margaret I

2015-03-18

HIV infection is a known risk factor for cancer but little is known about HIV testing patterns and the burden of HIV infection in cancer patients. We did a cross-sectional analysis to identify predictors of prior HIV testing and to quantify the burden of HIV in black cancer patients in Johannesburg, South Africa. The Johannesburg Cancer Case-control Study (JCCCS) recruits newly-diagnosed black cancer patients attending public referral hospitals for oncology and radiation therapy in Johannesburg . All adult cancer patients enrolled into the JCCCS from November 2004 to December 2009 and interviewed on previous HIV testing were included in the analysis. Patients were independently tested for HIV-1 using a single ELISA test . The prevalence of prior HIV testing, of HIV infection and of undiagnosed HIV infection was calculated. Multivariate logistic regression models were fitted to identify factors associated with prior HIV testing. A total of 5436 cancer patients were tested for HIV of whom 1833[33.7% (95% CI=32.5-35.0)] were HIV-positive. Three-quarters of patients (4092 patients) had ever been tested for HIV. The total prevalence of undiagnosed HIV infection was 11.5% (10.7-12.4) with 34% (32.0-36.3) of the 1833 patients who tested HIV-positive unaware of their infection. Men >49 years [OR 0.49(0.39-0.63)] and those residing in rural areas [OR 0.61(0.39-0.97)] were less likely to have been previously tested for HIV. Men with at least a secondary education [OR 1.79(1.11-2.90)] and those interviewed in recent years [OR 4.13(2.62 - 6.52)] were likely to have prior testing. Women >49 years [OR 0.33(0.27-0.41)] were less likely to have been previously tested for HIV. In women, having children associated with previous HIV testing. In a study of newly diagnosed black cancer patients in Johannesburg, over a third of HIV-positive patients were unaware of their HIV status. In South Africa black cancer patients should be targeted for opt-out HIV testing.
Dual turbine power plant and method of operating such plant, especially one having an HTGR steam supply

International Nuclear Information System (INIS)

Braytenbah, A.S.; Jaegtnes, K.O.

1977-01-01

A power plant including dual steam turbine-generators connected to pass superheat and reheat steam from a steam generator which derives heat from the coolant gas of a high temperature gas-cooled nuclear reactor is described. Associated with each turbine is a bypass line to conduct superheat steam in parallel with a high pressure turbine portion, and a bypass line to conduct superheat steam in parallel with a lower pressure turbine portion. Auxiliary steam turbines pass a portion of the steam flow to the reheater of the steam generator and drive gas blowers which circulate the coolant gas through the reactor and the steam source. Apparatus and method are disclosed for loading or unloading a turbine-generator while the other produces a steady power output. During such loading or unloading, the steam flows through the turbine portions are coordinated with the steam flows through the bypass lines for protection of the steam generator, and the pressure of reheated steam is regulated for improved performance of the gas blowers. 33 claims, 5 figures
Design and implementation of strategies for the assurance of quality for sterility testing in the Quality Control Section of the Chilean Nuclear Energy Commission

International Nuclear Information System (INIS)

Olave Carreno, Evelyn Karina

2015-01-01

The Department of Production and Service of the Chilean Nuclear Energy Commission (CCHEN), is an organization dedicated to the production and quality control of radioisotopes and radiopharmaceuticals. To be considered pharmaceutical specialties, the department has implemented a quality assurance system to guarantee compliance with the required standards during manufacturing processes, quality control and distribution. Such products are administered, mostly by via parental; that is why it is extremely important that as an injectable solution is sterile non-pyrogenic. Therefore, the Head of Quality Control Section emphasized the importance of validating sterility testing for these products. In the first instance we proceeded to update the related documentation, as this is one of the essential pillars of a good system of quality assurance, then continuing with the verification of compliance with the physical conditions of the place where the infertility tests are performed (classification of areas from a microbiological point of view). During this process, the proper training of personnel involved in performing environmental testing and sterility testing was performed. Finally, we proceeded to validate the sterility test by the method of direct inoculation three radiopharmaceuticals; also implemented sterility testing by membrane filtration method described in the USP. It was possible to validate the methods of direct inoculation and membrane filtration based on the validation protocol guidelines generated and previously approved by the Chief; demonstrating that in both cases the detection of reference strains of inocula is achieved under 100 cfu (Staphylococcus aureus, Bacillus spizizenii, Pseudomonas aeruginosa, Clostridium sporogenes, Candida albicans, Aspergillus brasiliensis), without interference of two of the products tested and interference of a product by direct inoculation method which was resolved. Based on these results, the documented evidence that
Associations of the stair climb power test with muscle strength and functional performance in people with COPD: A cross-sectional study

DEFF Research Database (Denmark)

Roig, Marc; Eng, Janice J.; MacIntyre, Donna L.

2010-01-01

associations of the SCPT with muscle strength (force-generating capacity) and functional performance. DESIGN: The study was a cross-sectional investigation. METHODS: Twenty-one people with COPD and a predicted mean (SD) percentage of forced expiratory volume in 1 second of 47.2 (12.9) and 21 people who were......: The observational design of the study and the use of a relatively small convenience sample limit the generalizability of the findings. CONCLUSIONS: The SCPT is a simple and safe test associated with measures of functional performance in people with COPD. People with COPD show deficits on the SCPT. However, the SCPT......BACKGROUND: The Stair Climb Power Test (SCPT) is a functional test associated with leg muscle power in older people. OBJECTIVE: The purposes of this study were to compare the results of the SCPT in people with chronic obstructive pulmonary disease (COPD) and people who were healthy and to explore...
Manufacturing of In-Pile Test Section(IPS) Mock-up for the 3-Pin Fuel Test Loop

Energy Technology Data Exchange (ETDEWEB)

Lee, J. M.; Park, K. N.; Chi, D. Y. (and others)

2005-10-15

Manufacturing process of IPS Mock-up was initiated in late of 2003 with DAEWOO Precision industries Company. Manufacturing drawings due to detail drawings are composed of Outer assembly and Inner assembly. Welding of IPS Mock-up was performed by the GMAW(Gas Metal Arc Welding) process. After the welding process, non-destructive examination was conducted. Leak test was performed to the Main cooling water part and Neon gas inter-space gap part by the He gas injection with the pressure of 6.0 kg{sub f}/cm{sup 2} and 30 minutes holding time. the result was shown that there was no leak at the Neon gas inter-space gap part but leak was occurred at Main cooling water part according to imperfect screw of purge plug. so, it was re-finished and test was performed to certify the leak tightness. To satisfy the HANARO Limiting Operation Condition, IPS should be tested ahead of installation at the HANARO reactor by the use of test facilities. IPS Mock-up and its test facilities will be designed and used for the test of 'HANARO flow tube pressure drop', 'IPS inner pressure drop' and 'IPS inner vibration'.
Validation of evaluated neutron standard cross sections

International Nuclear Information System (INIS)

Badikov, S.; Golashvili, T.

2008-01-01

Some steps of the validation and verification of the new version of the evaluated neutron standard cross sections were carried out. In particular: -) the evaluated covariance data was checked for physical consistency, -) energy-dependent evaluated cross-sections were tested in most important neutron benchmark field - 252 Cf spontaneous fission neutron field, -) a procedure of folding differential standard neutron data in group representation for preparation of specialized libraries of the neutron standards was verified. The results of the validation and verification of the neutron standards can be summarized as follows: a) the covariance data of the evaluated neutron standards is physically consistent since all the covariance matrices of the evaluated cross sections are positive definite, b) the 252 Cf spectrum averaged standard cross-sections are in agreement with the evaluated integral data (except for 197 Au(n,γ) reaction), c) a procedure of folding differential standard neutron data in group representation was tested, as a result a specialized library of neutron standards in the ABBN 28-group structure was prepared for use in reactor applications. (authors)
V/STOL Tandem Fan transition section model test. [in the Lewis Research Center 10-by-10 foot wind tunnel

Science.gov (United States)

Simpkin, W. E.

1982-01-01

An approximately 0.25 scale model of the transition section of a tandem fan variable cycle engine nacelle was tested in the NASA Lewis Research Center 10-by-10 foot wind tunnel. Two 12-inch, tip-turbine driven fans were used to simulate a tandem fan engine. Three testing modes simulated a V/STOL tandem fan airplane. Parallel mode has two separate propulsion streams for maximum low speed performance. A front inlet, fan, and downward vectorable nozzle forms one stream. An auxilliary top inlet provides air to the aft fan - supplying the core engine and aft vectorable nozzle. Front nozzle and top inlet closure, and removal of a blocker door separating the two streams configures the tandem fan for series mode operations as a typical aircraft propulsion system. Transition mode operation is formed by intermediate settings of the front nozzle, blocker door, and top inlet. Emphasis was on the total pressure recovery and flow distortion at the aft fan face. A range of fan flow rates were tested at tunnel airspeeds from 0 to 240 knots, and angles-of-attack from -10 to 40 deg for all three modes. In addition to the model variables for the three modes, model variants of the top inlet were tested in the parallel mode only. These lip variables were: aft lip boundary layer bleed holes, and Three position turning vane. Also a bellmouth extension of the top inlet side lips was tested in parallel mode.
Application of an empirical model in CFD simulations to predict the local high temperature corrosion potential in biomass fired boilers

International Nuclear Information System (INIS)

Gruber, Thomas; Scharler, Robert; Obernberger, Ingwald

2015-01-01

To gain reliable data for the development of an empirical model for the prediction of the local high temperature corrosion potential in biomass fired boilers, online corrosion probe measurements have been carried out. The measurements have been performed in a specially designed fixed bed/drop tube reactor in order to simulate a superheater boiler tube under well-controlled conditions. The investigated boiler steel 13CrMo4-5 is commonly used as steel for superheater tube bundles in biomass fired boilers. Within the test runs the flue gas temperature at the corrosion probe has been varied between 625 °C and 880 °C, while the steel temperature has been varied between 450 °C and 550 °C to simulate typical current and future live steam temperatures of biomass fired steam boilers. To investigate the dependence on the flue gas velocity, variations from 2 m·s −1 to 8 m·s −1 have been considered. The empirical model developed fits the measured data sufficiently well. Therefore, the model has been applied within a Computational Fluid Dynamics (CFD) simulation of flue gas flow and heat transfer to estimate the local corrosion potential of a wood chips fired 38 MW steam boiler. Additionally to the actual state analysis two further simulations have been carried out to investigate the influence of enhanced steam temperatures and a change of the flow direction of the final superheater tube bundle from parallel to counter-flow on the local corrosion potential. - Highlights: • Online corrosion probe measurements in a fixed bed/drop tube reactor. • Development of an empirical corrosion model. • Application of the model in a CFD simulation of flow and heat transfer. • Variation of boundary conditions and their effects on the corrosion potential
On the influence of water subcooling and melt jet parameters on debris formation

Energy Technology Data Exchange (ETDEWEB)

Manickam, Louis, E-mail: louis@safety.sci.kth.se; Kudinov, Pavel; Ma, Weimin; Bechta, Sevostian; Grishchenko, Dmitry

2016-12-01

Highlights: • Melt and water configuration effects on debris formation is studied experimentally. • Melt superheat and water subcooling are most influential compared to jet size. • Melt-water configuration and material properties influence particle fracture rate. • Results are compared with large scale experiments to study effect of spatial scales. - Abstract: Breakup of melt jet and formation of a porous debris bed at the base-mat of a flooded reactor cavity is expected during the late stages of a severe accident in light water reactors. Debris bed coolability is determined by the bed properties including particle size, morphology, bed height and shape as well as decay heat. Therefore understanding of the debris formation phenomena is important for assessment of debris bed coolability. A series of experiments was conducted in MISTEE-Jet facility by discharging binary-oxide mixtures of WO{sub 3}–Bi{sub 2}O{sub 3} and WO{sub 3}–ZrO{sub 2} into water in order to investigate properties of resulting debris. The effect of water subcooling, nozzle diameter and melt superheat was addressed in the tests. Experimental results reveal significant influence of water subcooling and melt superheat on debris size and morphology. Significant differences in size and morphology of the debris at different melt release conditions is attributed to the competition between hydrodynamic fragmentation of liquid melt and thermal fracture of the solidifying melt droplets. The particle fracture rate increases with increased subcooling. Further the results are compared with the data from larger scale experiments to discern the effects of spatial scales. The present work provides data that can be useful for validation of the codes used for the prediction of debris formation phenomena.
Superheat effect on bainite steel hardenability

International Nuclear Information System (INIS)

Kubachek, V.V.; Sklyuev, P.V.

1978-01-01

The bainite hardenability of 34KhN1M and 35 KhN1M2Ph steels has been investigated by the end-face hardening technique. It is established that, as the temperature of austenitization rises from 900 to 1280 deg C, the temperature of bainite transformation increases and bainite hardenability of the steels falls off. A repeated slow heating to 900 deg C of previously overheated 34KhN1M steel breaks up grain, lowers the temperature of the bainite transformation and raises the hardenability to values obtained with ordinary hardening from 900 deg C. A similar heating of previously overheated 35KhN1M2Ph steel is accompanied by restoration of initial coarse grains and maintenance of both the elevated bainite transformation temperature and to lower hardenability corresponding to hardening from the temperature of previous overheating
Conceptual Design for the In-Pile Test Section(IPS) Improvement

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Min; Shim, Bong Sik; Lee, Chung Young; Chi, Dae Young; Park, Su Ki; Ahn, Sung Ho; Kim, Young Ki; Lee, Kye Hong; Kim, Kwan Hyun

2009-01-15

Conceptual design on the IPS, instrumentation and 1/4' Tubing, test fuel supports, test fuel inspection station and inner assembly O-ring replacement was suggested for their improvement. There is a need Jacking bolt on the Top flange for the inner assembly disassemble from the outer assembly and the replacement about the top flange O-ring to metal gasket to secure pressure boundary. Mechanical sealing was suggested instead of brazing. Instrumentation and tubing route should be modified for the reduction of bending and protection from unexpected occasion. Concept on the test fuel inspection station under the consideration of canal dimension. Top flange Bolt handling tool, O-ring replacement platform and O-ring replacement tool was designed for the O-ring replacement at the inner assembly.
Testing of ENDF/B cross section data in the Californium-252 neutron benchmark field

International Nuclear Information System (INIS)

Mannhart, W.

1979-01-01

The fission neutron field of 252 Cf presently represents one of the most well-known neutron benchmark fields. For 13 neutron reactions which are of importance in reactor metrology, measurements of spectrum-averaged cross sections, [sigma], performed in this neutron field were compared with calculated average cross sections. This comparison allows one to draw conclusions as to the quality of different sigma(E) data taken from ENDF/B-IV, from ENDF/B-V, and from recent experiments and used in the calculation of average cross sections. The comparison includes an uncertainty analysis regarding the different uncertainty contributions of [sigma], of sigma(E), and of the spectral distribution of 252 Cf fission neutrons. Additionally, in a few examples, sensitivity studies were carried out. The sensitivity of the spectrum-averaged cross sections to individual characteristics of the sigma(E) data, such as normalization factors or shifts in the energy scale, was investigated. Similarly, the sensitivity of [sigma] to the spectral distribution of 252 Cf was determined. 4 figures, 2 tables
Utilization of Advanced Diagnostic Methods for Texture and Rut Depth Analysis on a Testing Pavement Section

Directory of Open Access Journals (Sweden)

Slabej Martin

2015-05-01

Full Text Available Qualitative characteristics of pavement in wide range reflects the pavement serviceability, which is a summary of the characteristics of the pavement, providing a fast, smooth, economical and especially safe driving of motor-vehicles. The target factor of pavement serviceability and safety of roads represents the quality of their surface properties. In the framework of research activities performed in the Research Centre founded under the auspices of University of Žilina, individual parameters of pavement serviceability were monitored by pavement surface scanning. This paper describes the creation of a 3D - road surface model and its analysis and evaluation from the viewpoint of two pavement serviceability parameters - the rut depth and texture. Measurements were performed on an experimental pavement section used contemporary in an Accelerated Pavement Testing experiment. The long-term goal is to ascertain functions predicting degradation of these two pavement serviceability parameters.
Utilization of HIV testing services among pregnant mothers in low income primary care settings in northern Ethiopia: a cross sectional study.

Science.gov (United States)

Alemu, Yihun Mulugeta; Ambaw, Fentie; Wilder-Smith, Annelies

2017-06-24

HIV testing of women in child bearing age is an entry point for preventing mother-to-child transmission of HIV (MTCT). This study aims to identify the proportion of women tested for HIV and to determine factors associated with utilization of HIV testing services among pregnant mothers in primary care settings in northern Ethiopia. A cross sectional study was conducted in 416 pregnant women from four primary care centers between October 2, 2012 and May 31, 2013 in East Gojjam, Ethiopia. The proportion of mothers who tested for HIV was 277(67%). Among mothers who were not tested for HIV, lack of HIV risk perception (n = 68, 49%) was a major self-reported barrier for HIV testing. A multivariable logistic regression analysis showed that those pregnant women who had comprehensive knowledge about MTCT had an Adjusted Odd Ratio (AOR) of 3.73 (95% CI: 1.56, 8.94), having comprehensive knowledge on prevention of mother to child transmission (PMTCT) of HIV an AOR of 2.56 (95% CI: 1.26, 5.19), and a favorable attitude towards persons living with HIV an AOR of 2.42 (95%CI, 1.20, 4.86) were more likely to be tested for HIV. One third of pregnant women had never been tested for HIV until the time of the study. Efforts should be made to improve mother's knowledge about MTCT and PMTCT to increase uptake of HIV testing. Enhancing mother's HIV risk perception to scale up HIV testing in resource limited setting is highly recommended.
Associations between cadmium exposure and neurocognitive test scores in a cross-sectional study of US adults.

Science.gov (United States)

Ciesielski, Timothy; Bellinger, David C; Schwartz, Joel; Hauser, Russ; Wright, Robert O

2013-02-05

Low-level environmental cadmium exposure and neurotoxicity has not been well studied in adults. Our goal was to evaluate associations between neurocognitive exam scores and a biomarker of cumulative cadmium exposure among adults in the Third National Health and Nutrition Examination Survey (NHANES III). NHANES III is a nationally representative cross-sectional survey of the U.S. population conducted between 1988 and 1994. We analyzed data from a subset of participants, age 20-59, who participated in a computer-based neurocognitive evaluation. There were four outcome measures: the Simple Reaction Time Test (SRTT: visual motor speed), the Symbol Digit Substitution Test (SDST: attention/perception), the Serial Digit Learning Test (SDLT) trials-to-criterion, and the SDLT total-error-score (SDLT-tests: learning recall/short-term memory). We fit multivariable-adjusted models to estimate associations between urinary cadmium concentrations and test scores. 5662 participants underwent neurocognitive screening, and 5572 (98%) of these had a urinary cadmium level available. Prior to multivariable-adjustment, higher urinary cadmium concentration was associated with worse performance in each of the 4 outcomes. After multivariable-adjustment most of these relationships were not significant, and age was the most influential variable in reducing the association magnitudes. However among never-smokers with no known occupational cadmium exposure the relationship between urinary cadmium and SDST score (attention/perception) was significant: a 1 μg/L increase in urinary cadmium corresponded to a 1.93% (95%CI: 0.05, 3.81) decrement in performance. These results suggest that higher cumulative cadmium exposure in adults may be related to subtly decreased performance in tasks requiring attention and perception, particularly among those adults whose cadmium exposure is primarily though diet (no smoking or work based cadmium exposure). This association was observed among exposure levels
14 CFR 35.40 - Functional test.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Functional test. 35.40 Section 35.40... STANDARDS: PROPELLERS Tests and Inspections § 35.40 Functional test. The variable-pitch propeller system must be subjected to the applicable functional tests of this section. The same propeller system used in...
40 CFR 53.64 - Test procedure: Static fractionator test.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test procedure: Static fractionator test. 53.64 Section 53.64 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Performance Characteristics of Class II Equivalent Methods for PM2.5 § 53.64 Test procedure: Static...
Fluidized bed combustion of refuse-derived fuel in presence of protective coal ash

Energy Technology Data Exchange (ETDEWEB)

Ferrer, Eduardo [CIRCE, Universidad de Zaragoza, Maria de Luna, 3, Zaragoza (Spain); Aho, Martti [VTT Processes, P.O. Box 1603, 40101 Jyvaeskylae (Finland); Silvennoinen, Jaani; Nurminen, Riku-Ville [Kvaerner Power, P.O.Box 109, FIN-33101 Tampere (Finland)

2005-12-15

Combustion of refuse-derived fuel (RDF) alone or together with other biomass leads to superheater fouling and corrosion in efficient power plants (with high steam values) due to vaporization and condensation of alkali chlorides. In this study, means were found to raise the portion of RDF to 40% enb without risk to boilers. This was done by co-firing RDF with coal and optimizing coal quality. Free aluminum silicate in coal captured alkalies from vaporized alkali chlorides preventing Cl condensation to superheaters. Strong fouling and corrosion were simultaneously averted. Results from 100 kW and 4 MW CFB reactors are reported. (author)

Adhesion Strength of Biomass Ash Deposits

DEFF Research Database (Denmark)

Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

2016-01-01

. Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash...... deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, ash/deposit composition......, sintering duration, and steel type on the adhesion strength....
Effects of Music during Multiple Cesarean Section Delivery.

Science.gov (United States)

Handan, Eren; Sahiner, Nejla Canbulat; Bal, Meltem Demirgoz; Dissiz, Melike

2018-03-01

This experimental study was conducted to determine the level of anxiety in women undergoing multiple cesarean section. Sixty multiple cesarean section referrals were randomly assigned to either the experimental or control groups. Data was collected at the Karaman Public Health Hospital in Turkey, from June 2015 to June 2016. Songs chosen earlier by the patients were played during the cesarean section procedure for the experimental group. The control group was studied without music. Data was collected using a questionnaire form, and Visual Analogue Scale (VAS) was used to determine the anxiety levels. The t-test and chi-square test were used to analyse statistically significant differences between the groups. The VAS scores before and during the procedure showed significantly lower scores for the experimental group, compared to the control group (p<0.05). Music therapy reduces the physiological and cognitive responses of anxiety in patients undergoing multiple cesarean section, and can be used in the clinical practice.
The integrity of 9Cr-1Mo to stainless steel transition joints in AGR steam generators

International Nuclear Information System (INIS)

James, D.W.; Neumann, P.; Soo, J.

1982-01-01

The metallurgical aspects of the transition joint between 9Cr-1Mo and 316 stainless steel boiler tube sections are reviewed. A large minimum superheat margin (106 0 C) between the dryout zone and the 9Cr-1Mo to stainless steel transition joint was specified in the original design to eliminate the risk of wetting the stainless steel which is susceptible to stress corrosion cracking. However, small defects were discovered in the welds between the 9Cr-1Mo and Sanicro (72%Ni-16%Cr-10%Fe) transition piece, resulting from dilution of the weld pool by nickel from the transition piece. This led to the possibility of weld failure as a result of creep crack growth in service, and any significant reduction in operating temperature would mean that the large superheat margin could not be sustained. The creep properties of the joints, together with the transition joint temperature distribution, enabled tube failure rates to be determined as a function of operating temperature. A probabilistic model was developed so that the transition joint could be operated within a temperature 'window', the lower temperature limit being determined by stress corrosion considerations and the upper limit being set by creep rate limitations. This allows full load performance from the boilers throughout the anticipated life of the plant. (author)
Knowledge, attitudes and practices of voluntary HIV counselling and testing among rural migrants in central China: a cross-sectional study.

Science.gov (United States)

Zhang, Tiejun; Zhang, Jinling; Gao, Meiyang; He, Na; Detels, Roger

2012-04-01

To document knowledge, attitudes and practices of voluntary HIV counselling and testing (VCT) among rural migrants in central China. A cross-sectional study with face-to-face anonymous questionnaire interviews was conducted using a structured questionnaire. Among 1280 participants, 87.9% reported having had sexual intercourse during their lifetime, with 69% of singles reporting having had sexual intercourse and 49.1% having had sex in the past month. Only 21% always used condoms, 84.4% knew HIV infection was diagnosed through blood testing, 56.6% had heard of VCT, but only 3.8% perceived their own risk for HIV infection. Only 43 (2.3%) had ever been tested for HIV, and none had ever been tested at a VCT site. About two-thirds (64.5%) would be willing to use VCT services upon awareness of HIV risk. A logistic regression model showed that females, those having little knowledge of HIV/AIDS, those unwilling to work with HIV-infected individuals, never having been tested for HIV and having low awareness regarding HIV risk were less willing to use VCT. The results of this study indicated that much greater efforts are needed to improve HIV/AIDS and VCT knowledge, to promote safer sex and to improve VCT acceptance among rural migrants in central China, particularly those engaging in risky behaviours.
Experimental Testing of Innovative Cold-Formed "GEB" Section / Badania Eksperymentalne Innowacyjnego Kształtownika Giętego Na Zimno Typu "Geb"

Science.gov (United States)

Łukowicz, Agnieszka; Urbańska-Galewska, Elżbieta; Gordziej-Zagórowska, Małgorzata

2015-03-01

One of the major advantages of light gauge steel structures made of cold-formed steel sections is their low weight so the production of typical single-storey steel structures of this kind of profiles is still rising. The well known profiles, e.o. Z-sections, C-sections and the so called hat-sections studied and described in the literature, are used mainly as purlins or truss components. A new profile GEB was patented for the use for primary load-bearing member in fabricated steel frames. According to the code [1] every novel cross section should be tested to assign the deformation shape and bearing capacity. The paper deals with the numerical and experimental research of bearing capacity of cold formed GEB profiles. The deformation shape and limit load was obtained from bending tests. The GEB cross section bearing capacity was also determined according to codes [1, 2]. Jedną z najważniejszych zalet lekkich konstrukcji metalowych, wytwarzanych z kształtowników giętych na zimno, jest ich mała masa, dlatego też, producenci coraz częściej wykorzystują możliwości profili giętych do wytwarzania typowych konstrukcji halowych w budownictwie systemowym. Proces gięcia na zimno, pozwala na formowanie różnego rodzaju przekrojów poprzecznych, które mogą być wykorzystywane jako elementy konstrukcji. Typowe kształty elementów. tzn. Z, C oraz tzw. przekroje kapeluszowe, które zostały przebadane i opisane w literaturze, wykorzystuje się głównie jako płatwie lub części składowe wiązarów kratowych. Nowo opatentowany przekrój typu GEB ma być wykorzystany jako element nośny konstrukcji ramowych. W związku z tym innowacyjny kształt oraz parametry geometryczne przekroju takiego kształtownika, związane z możliwością jego wyprodukowania oraz z warunkami nośności, stateczności oraz sztywności, muszą być optymalne. Według normy PN-EN 1993-1-3, każdy nowo uformowany przekrój powinien być przebadany pod kątem nośności elementu i formy
Status of neutron dosimetry cross sections

International Nuclear Information System (INIS)

Griffin, P.J.; Kelly, J.G.

1992-01-01

Several new cross section libraries, such as ENDF/B-VI(release 2), IRDF-90,JEF-2.2, and JENDL-3 Dosimetry, have recently been made available to the dosimetry community. the Sandia National Laboratories (SNL) Radiation Metrology Laboratory (RML) has worked with these libraries since pre-release versions were available. this paper summarizes the results of the intercomparison and testing of dosimetry cross sections. As a result of this analysis, a compendium of the best dosimetry cross sections was assembled from the available libraries for use within the SNL RML. this library, referred to as the SNLRML Library, contains 66 general dosimetry sensors and 3 special dosimeters unique to the RML sensor inventory. The SNLRML cross sections have been put into a format compatible with commonly used spectrum determination codes
Testing of cross-section functionals in the unresolved resonance region

International Nuclear Information System (INIS)

Koshcheev, V.N.; Krivtsov, A.S.; Sinitsa, V.V.; Ukraintsev, V.F.

1994-01-01

The results of a comparison of the GRUCON, MMK and NJOY data processing codes in the treatment of evaluated neutron data in the unresolved resonance region are presented. The sets of average resonance parameters of 238 U and 239 Pu isotopes, which have been published by Munos-Cobos et al., and Ribon et al., were used in this exercise. Average cross-sections, self-shielding factors and Doppler broadening self-shielding factors are compared with the original results presented by the above-mentioned authors. Conclusions regarding the reliability of the neutron data processing codes are made. (author). 6 refs, 7 tabs
Effect of home-based HIV counselling and testing on stigma and risky sexual behaviours: serial cross-sectional studies in Uganda.

Science.gov (United States)

Nuwaha, Fred; Kasasa, Simon; Wana, Godwill; Muganzi, Elly; Tumwesigye, Elioda

2012-06-04

A large, district-wide, home-based HIV counselling and testing (HBHCT) programme was implemented in Bushenyi district of Uganda from 2004 to 2007. This programme provided free HBHCT services to all consenting adults of Bushenyi district and had a very high uptake and acceptability. We measured population-level changes in knowledge of HIV status, stigma and HIV-risk behaviours before and after HBHCT to assess whether widespread HBHCT had an effect on trends of risky sexual behaviours and on stigma and discrimination towards HIV. Serial cross-sectional surveys were carried out before and after the implementation of HBHCT programme in Bushenyi district of Uganda. A total of 1402 randomly selected adults (18 to 49 years) were interviewed in the baseline survey. After the implementation, a different set of randomly selected 1562 adults was interviewed using the same questionnaire. Data was collected on socio-demographic characteristics, sexual behaviour, whether respondents had ever tested for HIV and stigma and discrimination towards HIV/AIDS. The proportion of people who had ever tested for HIV increased from 18.6% to 62% (pHIV test result with a sexual partner increased from 41% to 57% (pHIV services especially in areas where access to HCT is low.
Meeting cross-section requirements for nuclear-energy design

Energy Technology Data Exchange (ETDEWEB)

Weisbin, C.R.; de Saussure, G.; Santoro, R.T. (Oak Ridge National Lab., TN (USA)); Gilai, T. (Ben-Gurion Univ. of the Negev, Beersheba (Israel))

1982-01-01

Current requirements in cross-section data that are essential to nuclear-energy programmes are summarized and explained and some insight into how these data might be obtained is provided. The six sections of the paper describe: design parameters and target accuracies; data collection, evaluation and analysis; determination of high-accuracy differential nuclear data for technological applications; status of selected evaluated nuclear data; analysis of benchmark testing; identification of important cross sections and inferred needs.
Dielectronic recombination cross sections for H-like ions

International Nuclear Information System (INIS)

Pindzola, M.S.; Badnell, N.R.; Griffin, D.C.

1990-01-01

Dielectronic recombination cross sections for several H-like atomic ions are calculated in an isolated-resonance, distorted-wave approximation. Fine-structure and configuration-interaction effects are examined in detail for the O 7+ cross section. Hartree-Fock, intermediate-coupled, multiconfiguration dielectronic recombination cross sections for O 7+ are then compared with the recent experimental measurements obtained with the Test Storage Ring in Heidelberg. The cross-section spectra line up well in energy and the shape of the main resonance structures are comparable. The experimental integrated cross sections differ by up to 20% from theory, but this may be due in part to uncertainties in the electron distribution function
Dissimilar weld failure analysis and development program

International Nuclear Information System (INIS)

Holko, K.H.; Li, C.C.

1982-01-01

The problem of dissimilar weld cracking and failure is examined. This problem occurs in boiler superheater and reheater sections as well as main steam piping. Typically, a dissimilar weld joins low-alloy steel tubing such as Fe-2-1/4 Cr-1Mo to stainless steel tubing such as 321H and 304H. Cracking and failure occur in the low-alloy steel heat-affected zone very close to the weld interface. The 309 stainless steel filler previously used has been replaced with nickel-base fillers such as Inconel 132, Inconel 182, and Incoweld A. This change has extended the time to cracking and failure, but has not solved the problem. To illustrate and define the problem, the metallography of damaged and failed dissimilar welds is described. Results of mechanical tests of dissimilar welds removed from service are presented, and factors believed to be influential in causing damage and failure are discussed. In addition, the importance of dissimilar weldment service history is demonstrated, and the Dissimilar Weld Failure Analysis and Development Program is described. 15 figures
Initial pressure spike and its propagation phenomena in sodium-water reaction tests for MONJU steam generators

International Nuclear Information System (INIS)

Sato, M.; Hiroi, H.; Tanaka, N.; Hori, M.

1977-01-01

With the objective of demonstrating the safe design of steam generators for prototype LMFBR MONJU against the postulated large-leak accident, a number of large-leak sodium-water reaction tests have been conducted using the SWAT-1 and SWAT-3 rigs. Investigation of the potential effects of pressure load on the system is one of the major concerns in these tests. This paper reports the behavior of initial pressure spike in the reaction vessel, its propagation phenomena to the simulated secondary cooling system, and the comparisons with the computer code for one-dimensional pressure wave propagation problems. Both rigs used are the scaled-down models of the helically coiled steam generators of MONJU. The SWAT-1 rig is a simplified model and consists of a reaction vessel (1/8 scale of MONJU evaporator with 0.4 m dia. and 2.5 m height) and a pressure relief system i.e., a pressure relief line and a reaction products tank. On the other hand, the SWAT-3 rig is a 1/2.5 scale of MONJU SG system and consists of an evaporator (reaction vessel with 1.3 m dia. and 6.35 m height), a superheater, an intermediate heat exchanger (IHX), a piping system simulating the secondary cooling circuit and a pressure relief system. The both water injection systems consist of a water injection line with a rupture disk installed in front of injection hole and an electrically heated water tank. Choice of water injection rates in the scaled-down models is made based on the method of iso-velocity modeling. Test results indicated that the characteristics of the initial pressure spike are dominated by those of initial water injection which are controlled by the conditions of water heater and the size of water injection hole, etc
Tests of three tapered airfoils based on the N.A.C.A. 2200, the N.A.C.A.-M6, and the Clark Y sections

Science.gov (United States)

Anderson, Raymond F

1934-01-01

Three tapered airfoils based on the N.A.C.A. 2200, the N.A.C.A.-M6, and the Clark Y sections were tested in the variable-density wind tunnel at a Reynolds Number of approximately 3,100,000. The models, which were of aspect ratio 6, had constant core center sections and rounded tips, and tapered in thickness from 18 percent at the roots to 9 percent at the tips. The aerodynamic characteristics are given by the usual dimensionless coefficients plotted for both positive and negative angles of attack and by effective profile-drag coefficients plotted against lift coefficients.
ENDF/B Thermal Data Testing

CERN Document Server

McCrosson, F J

2001-01-01

The thermal data testing group is concerned with establishing the merit of ENDF/B cross sections for the analysis of thermal systems. The integral experiments used in the testing are designed to analyze each of the phenomena identified in the familiar four-factor formula. For brevity, only the testing of the cross sections in uranium systems is described in this report.
Automated Cross-Sectional Measurement Method of Intracranial Dural Venous Sinuses.

Science.gov (United States)

Lublinsky, S; Friedman, A; Kesler, A; Zur, D; Anconina, R; Shelef, I

2016-03-01

MRV is an important blood vessel imaging and diagnostic tool for the evaluation of stenosis, occlusions, or aneurysms. However, an accurate image-processing tool for vessel comparison is unavailable. The purpose of this study was to develop and test an automated technique for vessel cross-sectional analysis. An algorithm for vessel cross-sectional analysis was developed that included 7 main steps: 1) image registration, 2) masking, 3) segmentation, 4) skeletonization, 5) cross-sectional planes, 6) clustering, and 7) cross-sectional analysis. Phantom models were used to validate the technique. The method was also tested on a control subject and a patient with idiopathic intracranial hypertension (4 large sinuses tested: right and left transverse sinuses, superior sagittal sinus, and straight sinus). The cross-sectional area and shape measurements were evaluated before and after lumbar puncture in patients with idiopathic intracranial hypertension. The vessel-analysis algorithm had a high degree of stability with <3% of cross-sections manually corrected. All investigated principal cranial blood sinuses had a significant cross-sectional area increase after lumbar puncture (P ≤ .05). The average triangularity of the transverse sinuses was increased, and the mean circularity of the sinuses was decreased by 6% ± 12% after lumbar puncture. Comparison of phantom and real data showed that all computed errors were <1 voxel unit, which confirmed that the method provided a very accurate solution. In this article, we present a novel automated imaging method for cross-sectional vessels analysis. The method can provide an efficient quantitative detection of abnormalities in the dural sinuses. © 2016 by American Journal of Neuroradiology.
Rocketball Test Facility

Data.gov (United States)

Federal Laboratory Consortium — This test facility offers the capability to emulate and measure guided missile radar cross-section without requiring flight tests of tactical missiles. This facility...
49 CFR 179.500-7 - Physical tests.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Physical tests. 179.500-7 Section 179.500-7...-7 Physical tests. (a) Physical tests shall be made on two test specimens 0.505 inch in diameter... tank. These test specimen ring sections or prolongations shall be heat treated, with the necked-down...
Selective reporting of antibiotic susceptibility test results in European countries: an ESCMID cross-sectional survey.

Science.gov (United States)

Pulcini, Céline; Tebano, Gianpiero; Mutters, Nico T; Tacconelli, Evelina; Cambau, Emmanuelle; Kahlmeter, Gunnar; Jarlier, Vincent

2017-02-01

Selective reporting of antibiotic susceptibility test (AST) results is one possible laboratory-based antibiotic stewardship intervention. The primary aim of this study was to identify where and how selective reporting of AST results is implemented in Europe both in inpatient and in outpatient settings. An ESCMID cross-sectional, self-administered, internet-based survey was conducted among all EUCIC (European Committee on Infection Control) or EUCAST (European Committee on Antimicrobial Susceptibility Testing) national representatives in Europe and Israel. Of 38 countries, 36 chose to participate in the survey. Selective reporting of AST results was implemented in 11/36 countries (31%), was partially implemented in 4/36 (11%) and was limited to local initiatives or was not adopted in 21/36 (58%). It was endorsed as standard of care by health authorities in only three countries. The organisation of selective reporting was everywhere discretionally managed by each laboratory, with a pronounced intra- and inter-country variability. The most frequent application was in uncomplicated community-acquired infections, particularly urinary tract and skin and soft-tissue infections. The list of reported antibiotics ranged from a few first-line options, to longer reports where only last-resort antibiotics were hidden. Several barriers to implementation were reported, mainly lack of guidelines, poor system support, insufficient resources, and lack of professionals' capability. In conclusion, selective reporting of AST results is poorly implemented in Europe and is applied with a huge heterogeneity of practices. Development of an international framework, based on existing initiatives and identified barriers, could favour its dissemination as one important element of antibiotic stewardship programmes. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.
MCO Engineering Test Report Fuel Basket Handling Grapple Acceptance Test

International Nuclear Information System (INIS)

CHENAULT, D.M.

2000-01-01

Acceptance testing of the production SNF Fuel Basket lift grapples to the required 150 percent maximum lift load is documented herein. The report shows the results affirming the proof test passage. The primary objective of this test was to confirm the load rating of the grapple per applicable requirements of ANSI 14 6 American National Standard For Radioactive Materials Special Lifting Devices for Shipping Containers Weighing 10,000 pounds (4500kg) or More. The above Standard requires a load test of 150% of the design load which must be held for a minimum of 10 minutes followed by a Liquid Penetrant or Magnetic Particle examination of critical areas and welds in accordance with the ANSI/ASME Boiler and Pressure Vessel Code 1989 Section 111 Division 1 section NF 5350
Thermo-Economic Performance Analysis of a Regenerative Superheating Organic Rankine Cycle for Waste Heat Recovery

Directory of Open Access Journals (Sweden)

Zhonghe Han

2017-10-01

Full Text Available The Organic Rankine Cycle (ORC is a promising form of technology for recovering low-grade waste heat. In this study, a regenerative ORC system is established to recover the waste flue gas of 160 °C. Focusing on thermodynamic and economic performance while simultaneously considering the limitations of volume flow ratio (VFR and the effect of superheat, working fluid selection and parameter optimization have been investigated. The optimization of the evaporation temperature is carried out by analyzing the variation of net power output and specific investment cost (SIC. Then, the net power output, specific net power output, total exergy destruction rate, VFR, total capital cost, and levelized electricity cost (LEC are selected as criteria, and a fuzzy multi-criteria evaluation method is adopted to select a more suitable working fluid and determine the optimal degree of superheat. In addition, the preheating coefficient, latent heat coefficient, superheating coefficient, and internal heat coefficient were proposed to explore the effect of working fluid critical temperature on thermal efficiency. Research studies demonstrate that there is an optimal evaporation temperature, maximizing net power output and minimizing the SIC. Isohexane and butane have greater specific net power output due to greater latent heat. A suitable degree of superheat is not only conducive to improving the working capacity of working fluids, but also reduces the VFR, total capital cost, SIC, and LEC for different working fluids. Thus, the system’s thermodynamic and economic performance—as well as the operational stability—are improved. Among the six working fluids, butane exhibits the best comprehensive performance, and its optimal evaporation temperature and degree of superheat are 100 °C and 5 °C, respectively.

Wastage-resistant characteristics of 12Cr steel tube material. Small leak sodium-water reaction test

International Nuclear Information System (INIS)

Shimoyama, Kazuhito

2004-03-01

In the water leak accident of a steam generator designed for a sodium cooled reactor in the Feasibility Study, the localization of tube failure propagation by using an advanced water leak detector will be required from the viewpoints of the safety and economical efficiency of the plant. So far, the conventional knowledge and analytical tools have been used in the investigation and evaluation of water leak phenomenon; nevertheless, there was neither test data nor the study of quantitative evaluation on the corrosion behavior, so-called wastage-resistant characteristics, of 12Cr steel tube material in sodium-water reactions. Wastage tests for the 12Cr steel tube material were conducted in small water leaks by use of the Sodium-Water Reaction Test Rig (SWAT-1R), and the data of wastage rate were obtained in the parameter of water leak rate under the constant sodium temperature and distance between leak and target tubes. The test results lead to the following conclusions: (1) The wastage-resistibility of 12Cr steel is 1.6 times greater than that of 9Cr steel and is 2.7 times greater than that of 2.25Cr-1Mo steel. (2)The wastage-resistibility of 12Cr steel increases in smaller water leaks; especially in water leak rates of 1 g/sec or less, it is more excellent than that of SUS321 stainless steel used as Monju superheater tube material. (3) Based on the correlation of wastage rate for the 9Cr steel, the correlation for the 12Cr steel has been obtained to be used for the evaluation of tube failure propagation. As the correlation of wastage rate for the 12Cr steel is based on the correlation for the 9Cr steel, it gives enough conservatism in smaller water leaks. To serve in accurately evaluating the tube failure propagation in smaller water leaks, it is necessary to obtain new correlation of wastage rate for the 12Cr steel based on the data in the wide range of water leak rates. (author)
Demonstration test for reliability of valves for atomic power plants

International Nuclear Information System (INIS)

Hosaka, Shiro

1978-01-01

The demonstration test on the reliability of valves for atomic power plants being carried out by the Nuclear Engineering Test Center is reported. This test series is conducted as six-year project from FY 1976 to FY 1981 at the Isogo Test Center. The demonstration test consists of (1) environmental test, (2) reaction force test, (3) vibration test, (4) stress measurement test, (5) operational characteristic test, (6) flow resistance coefficient measuring test, (7) leakage test and (8) safety valve and relief valve test. These contents are explained about the special requirements for nuclear use, for example, the enviornmental condition after the design base accident of PWRs and BWRs, the environmental test sequence for isolation valves of containment vessels under the emergency condition, the seismic test condition for valves of nuclear use, the various stress measurements under thermal transient conditions, the leak test after 500 cycles between the normal operating conditions for PWRs and BWRs and the start up conditions and so on. As for the testing facilities, the whole flow diagram is shown, in which the environmental test section, the vibration test section, the steam test section, the hot water test section, the safety valve test section and main components are included. The specifications of each test section and main components are presented. (Nakai, Y.)
Power plant and system for accelerating a cross compound turbine in such plant, especially one having an HTGR steam supply

International Nuclear Information System (INIS)

Jaegtnes, K.O.; Braytenbah, A.S.

1979-01-01

In accordance with the present invention, a power plant includes a steam source to generate superheat and reheat steam which flows through a turbine-generator and an associated bypass system. A high-pressure and an intermediate-pressure turbine portion drive a first electrical generating means, and a low-pressure turbine portion drives a second electrical generating means. A first flow of superheat steam flows through the high-pressure portion, while a second flow of reheat steam flows through the intermediate and low-pressure portions in succession. Provision is made for bypassing steam around the turbine portions; in particular, one bypass means permits a flow of superheat steam from the steam source to the exhaust of the high-pressure portion, and another bypass means allows reheated steam to pass from the source to the exhaust of the low-pressure portion. The first and second steam flows are governed independently. While one of such flows is varied for purposes of controlling the rotational speed of the first generating means according to a desired speed, the other flow is varied to regulate a power plant variable at its desired level. (author)
Vapor generation rate model for dispersed drop flow

International Nuclear Information System (INIS)

Unal, C.; Tuzla, K.; Cokmez-Tuzla, A.F.; Chen, J.C.

1991-01-01

A comparison of predictions of existing nonequilibrium post-CHF heat transfer models with the recently obtained rod bundle data has been performed. The models used the experimental conditions and wall temperatures to predict the heat flux and vapor temperatures at the location of interest. No existing model was able to reasonably predict the vapor superheat and the wall heat flux simultaneously. Most of the models, except Chen-Sundaram-Ozkaynak, failed to predict the wall heat flux, while all of the models could not predict the vapor superheat data or trends. A recently developed two-region heat transfer model, the Webb-Chen two-region model, did not give a reasonable prediction of the vapor generation rate in the far field of the CHF point. A new correlation was formulated to predict the vapor generation rate in convective dispersed droplet flow in terms of thermal-hydraulic parameters and thermodynamic properties. A comparison of predictions of the two-region heat transfer model, with the use of a presently developed correlation, with all the existing post-CHF data, including single-tube and rod bundle, showed significant improvements in predicting the vapor superheat and tube wall heat flux trends. (orig.)
Science Library of Test Items. Volume Thirteen. Mastery Testing Program. [Mastery Tests Series 5.] Tests M51-M65.

Science.gov (United States)

New South Wales Dept. of Education, Sydney (Australia).

As part of a series of tests to measure mastery of specific skills in the natural sciences, copies of tests 51 through 65 include: (51) interpreting atomic and mass numbers; (52) extrapolating from a geological map; (53) matching geological sections and maps; (54) identifying parts of the human eye; (55) identifying the functions of parts of a…
GRE math tests

CERN Document Server

Kolby, Jeff

2014-01-01

Twenty-three GRE Math Tests! The GRE math section is not easy. There is no quick fix that will allow you to ""beat"" the section. But GRE math is very learnable. If you study hard and master the techniques in this book, your math score will improve--significantly! The GRE cannot be ""beaten."" But it can be mastered--through hard work, analytical thought, and by training yourself to think like a test writer. Many of the problems in this book are designed to prompt you to think like a test writer. For example, you will find ""Duals."" These are pairs of similar problems in which only one prop
Fail-safety of the EBR-II steam generator system

International Nuclear Information System (INIS)

Chopra, P.S.; Stone, C.C.; Hutter, E.; Barney, W.K.; Staker, R.G.

1976-01-01

Fail-safe analyses of the EBR-II steam-generator system show that a postulated non-instantaneous leak of water or steam into sodium, through a duplex tube or a tubesheet, at credible leak rates will not structurally damage the evaporators and superheaters. However, contamination of the system and possible shell wastage by sodium-water reaction products may render the system inoperable for a period exceeding six months. This period would be shortened to three months if the system were modified by adding a remotely operated water dump system, a steam vent system, a secondary sodium superheater relief line, and a tubesheet leak-detection system
A physical model of the evaporating meniscus

International Nuclear Information System (INIS)

Mirzamoghadam, A.; Catton, I.

1985-01-01

Transport phenomena associated with the heating of a saturated stationary fluid near saturation by an inclined, partially submerged copper plate was studied analytically. Under steady state evaporation, the meniscus profile was derived using an appropriate liquid film velocity and temperature distribution in an integral approach. The solution was then back-substituted in order to identify regions of influence of various physical phenomena given the fluid properties, wall superheat and plate tilt. The degree of superheat and wall tilt were seen to control instability in the meniscus. This instability, connected to the experimental observation of meniscus oscillation, was credited to contributions by liquid inertia and Marangoni convection
Preliminary Options Assessment of Versatile Irradiation Test Reactor

Energy Technology Data Exchange (ETDEWEB)

Sen, Ramazan Sonat [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-01-01

The objective of this report is to summarize the work undertaken at INL from April 2016 to January 2017 and aimed at analyzing some options for designing and building a versatile test reactor; the scope of work was agreed upon with DOE-NE. Section 2 presents some results related to KNK II and PRISM Mod A. Section 3 presents some alternatives to the VCTR presented in [ ] as well as a neutronic parametric study to assess the minimum power requirement needed for a 235U metal fueled fast test reactor capable to generate a fast (>100 keV) flux of 4.0 x 1015 n /cm2-s at the test location. Section 4 presents some results regarding a fundamental characteristic of test reactors, namely displacement per atom (dpa) in test samples. Section 5 presents the INL assessment of the ANL fast test reactor design FASTER. Section 6 presents a summary.
On Preliminary Test Estimator for Median

OpenAIRE

Okazaki, Takeo; 岡崎, 威生

1990-01-01

The purpose of the present paper is to discuss about estimation of median with a preliminary test. Two procedures are presented, one uses Median test and the other uses Wilcoxon two-sample test for the preliminary test. Sections 3 and 4 give mathematical formulations of such properties, including mean square errors with one specified case. Section 5 discusses their optimal significance levels of the preliminary test and proposes their numerical values by Monte Carlo method. In addition to mea...
LHCb cross-section measurements with heavy flavour jets

CERN Multimedia

Michielin, Emanuele

2017-01-01

Cross-section measurements of jets originating from the hadronization of beauty ($b$) and charm ($c$) quarks at LHCb give the unique opportunity to probe Parton Distribution Functions (PDFs) at low and large momentum fraction and to test the Standard Model in the forward region. In this poster the production of $t\\bar{t}$ pairs in the forward region, the measurement of the $W+b\\bar{b}$ and $W+c\\bar{c}$ cross-section and the measurement of the $Z\\rightarrow b\\bar{b}$ cross-section are presented.
A comparison between burn-out data for 19-rod cluster test-sections cooled by Freon-12 at 155 lb/in2 (abs), and by water at 1000 lb/in2 in vertical upflow

International Nuclear Information System (INIS)

Stevens, G.F.; Wood, R.W.

1966-01-01

Previous experiments on the Winfrith Freon Rig have produced scaling factors which relate these Freon experiments to the corresponding experiments in water with an accuracy of about 10%. It has also been found that the Freon rig is accurate, economical and easy to use. The scaling factors so obtained have now been tested against data for 19-rod clusters which had previously been tested at Columbia University. This report presents the results of the rod cluster tests in which comparison is made between Freon-12 and water for three test-sections which differ in the means of spacing the individual rods. All the test-sections were heated uniformly with respect to length, but had a radial flux depression of nominally 0.70/1.0. The results provide strong evidence that the scaling factor method using Freon-12 at 155 lb/in 2 (abs) is a useful technique for predicting the behaviour at burn-out of complicated test-sections cooled by boiling water at 1000 lb/in 2 with only one-eighteenth of the power required for the water experiment. In particular, the Freon tests reproduce closely the relative burn-out powers previously measured in water. It has also been found that repeated rebuilding of a nominally unchanged cluster from the same components can produce burn-out powers differing by ± 6%. This new result illustrates the power and value of the Freon technique. (author)
40 CFR 1039.505 - How do I test engines using steady-state duty cycles, including ramped-modal testing?

Science.gov (United States)

2010-07-01

...-state duty cycles, including ramped-modal testing? 1039.505 Section 1039.505 Protection of Environment... duty cycles, including ramped-modal testing? This section describes how to test engines under steady-state conditions. In some cases, we allow you to choose the appropriate steady-state duty cycle for an...
Cross sections required for FMIT dosimetry

International Nuclear Information System (INIS)

Gold, R.; McElroy, W.N.; Lippincott, E.P.; Mann, F.M.; Oberg, D.L.; Roberts, J.H.; Ruddy, F.H.

1980-01-01

The Fusion Materials Irradiation Test (FMIT) facility, currently under construction, is designed to produce a high flux of high energy neutrons for irradiation effects experiments on fusion reactor materials. Characterization of the flux-fluence-spectrum in this rapidly varying neutron field requires adaptation and extension of currently available dosimetry techniques. This characterization will be carried out by a combination of active, passive, and calculational dosimetry. The goal is to provide the experimenter with accurate neutron flux-fluence-spectra at all positions in the test cell. Plans have been completed for a number of experimental dosimetry stations and provision for these facilities has been incorporated into the FMIT design. Overall needs of the FMIT irradiation damage program delineate goal accuracies for dosimetry that, in turn, create new requirements for high energy neutron cross section data. Recommendations based on these needs have been derived for required cross section data and accuracies
Deposition and high temperature corrosion in a 10 MW straw

DEFF Research Database (Denmark)

Michelsen, Hanne Philbert; Frandsen, Flemming; Dam-Johansen, Kim

1998-01-01

Deposition and corrosion measurements were conducted at a 10 MW wheat straw fired stoker boiler used for combined power and heat production. The plant experiences major problems with deposits on the heat transfer surfaces, and test probes have shown enhanced corrosion due to selective corrosion...... for metal temperatures above 520 C. Deposition measurements carried out at a position equal to the secondary superheater showed deposits rich in potassium and chlorine and to a lesser extent in silicon, calcium, and sulfur. Potassium and chlorine make up 40-80 wt% of the deposits. Mechanisms of deposit...
Get Tested for Colorectal Cancer

Science.gov (United States)

... Print This Topic En español Get Tested for Colorectal Cancer Browse Sections The Basics Overview What to Expect ... section Overview 2 of 6 sections The Basics: Colorectal Cancer What is colorectal cancer? Colorectal cancer is a ...
Thermohydraulic tests in nuclear fuel model

International Nuclear Information System (INIS)

Ladeira, L.C.D.; Navarro, M.A.

1984-01-01

The main experimental works performed in the Thermohydraulics Laboratory of the NUCLEBRAS Nuclear Technology Development Center, in the field of thermofluodynamics are briefly described. These works include the performing of steady-state flow tests in single tube test sections, and the design and construction of a rod bundle test section, which will be also used for those kind of testes. Mention is made of the works to be performed in the near future, related to steady-state and transient flow tests. (Author) [pt
9 CFR 113.39 - Cat safety tests.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cat safety tests. 113.39 Section 113... Procedures § 113.39 Cat safety tests. The safety tests provided in this section shall be conducted when... recommended for use in cats. (a) The cat safety test provided in this paragraph shall be used when the Master...
40 CFR 89.410 - Engine test cycle.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine test cycle. 89.410 Section 89... Procedures § 89.410 Engine test cycle. (a) Emissions shall be measured using one of the test cycles specified...) through (a)(4) of this section. These cycles shall be used to test engines on a dynamometer. (1) The 8...
9 CFR 113.40 - Dog safety tests.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Dog safety tests. 113.40 Section 113... Procedures § 113.40 Dog safety tests. The safety tests provided in this section shall be conducted when... recommended for use in dogs. Serials which are not found to be satisfactory when tested pursuant to the...

Will an unsupervised self-testing strategy for HIV work in health care workers of South Africa? A cross sectional pilot feasibility study.

Science.gov (United States)

Pant Pai, Nitika; Behlim, Tarannum; Abrahams, Lameze; Vadnais, Caroline; Shivkumar, Sushmita; Pillay, Sabrina; Binder, Anke; Deli-Houssein, Roni; Engel, Nora; Joseph, Lawrence; Dheda, Keertan

2013-01-01

In South Africa, stigma, discrimination, social visibility and fear of loss of confidentiality impede health facility-based HIV testing. With 50% of adults having ever tested for HIV in their lifetime, private, alternative testing options are urgently needed. Non-invasive, oral self-tests offer a potential for a confidential, unsupervised HIV self-testing option, but global data are limited. A pilot cross-sectional study was conducted from January to June 2012 in health care workers based at the University of Cape Town, South Africa. An innovative, unsupervised, self-testing strategy was evaluated for feasibility; defined as completion of self-testing process (i.e., self test conduct, interpretation and linkage). An oral point-of-care HIV test, an Internet and paper-based self-test HIV applications, and mobile phones were synergized to create an unsupervised strategy. Self-tests were additionally confirmed with rapid tests on site and laboratory tests. Of 270 health care workers (18 years and above, of unknown HIV status approached), 251 consented for participation. Overall, about 91% participants rated a positive experience with the strategy. Of 251 participants, 126 evaluated the Internet and 125 the paper-based application successfully; completion rate of 99.2%. All sero-positives were linked to treatment (completion rate:100% (95% CI, 66.0-100). About half of sero-negatives were offered counselling on mobile phones; completion rate: 44.6% (95% CI, 38.0-51.0). A majority of participants (78.1%) were females, aged 18-24 years (61.4%). Nine participants were found sero-positive after confirmatory tests (prevalence 3.6% 95% CI, 1.8-6.9). Six of nine positive self-tests were accurately interpreted; sensitivity: 66.7% (95% CI, 30.9-91.0); specificity:100% (95% CI, 98.1-100). Our unsupervised self-testing strategy was feasible to operationalize in health care workers in South Africa. Linkages were successfully operationalized with mobile phones in all sero
Factors associated with HIV testing among young men who have sex with men in Myanmar: a cross-sectional study.

Science.gov (United States)

Pham, Minh D; Aung, Poe Poe; Paing, Aye Kyawt; Pasricha, Naanki; Agius, Paul A; Tun, Waimar; Bajracharya, Ashish; Luchters, Stanley

2017-11-01

In Myanmar, men who have sex with men (MSM) experience high risk of HIV infection. However, access to HIV testing and prevention services remains a challenge among this marginalized population. The objective of this study was to estimate population prevalence and correlates of prior HIV testing among young MSM (YMSM) and informs the development of HIV testing and intervention programmes that respond to the specific needs of this population. Five hundred and eighty-five YMSM aged 18 to 24 years were recruited using respondent-driven sampling (RDS) in a cross-sectional survey conducted in six townships of Myanmar. RDS-adjusted population estimates were calculated to estimate prevalence of HIV testing; RDS-weighted logistic regression was used to examine correlates of HIV testing in the past 6 months and in a lifetime. There were 12 participants who reported receiving a HIV-positive test; of those, five were tested in the past 6 months. The RDS-weighted prevalence estimates of lifetime (any prior) HIV testing was 60.6% (95% CI: 53.3% to 66.4%) and of recent (≤ 6 months) HIV testing was 50.1% (95% CI: 44.1% to 55.5%). In multivariable analysis, sexual identity was associated with lifetime but not recent HIV testing. Lifetime and recent HIV testing were associated with having three or more male sexual partners in the past 12 months (adjusted ORs (aORs) = 2.28, 95% CIs: 1.21 to 4.32 and 2.69, 95% CI: 1.59 to 4.56), having good HIV-related knowledge (aORs = 1.96, 95% CIs: 1.11 to 3.44 and 1.77, 95% CI: 1.08 to 2.89), reporting high HIV testing self-efficacy (aORs = 13.5, 95% CIs: 6.0 to 30.1 and 9.81, 95% CI: 4.27 to 22.6) and having access to and use of non-HIV health-related services in the past 12 months (aORs = 13.2, 95% CIs: 6.85 to 25.6 and 7.15, 95% CI: 4.08 to 12.5) respectively. HIV testing coverage among YMSM aged 18 to 24 years old in Myanmar is still suboptimal. Integrated HIV testing and prevention services in existing health service
Power technology complex for production of motor fuel from brown coals with power supply from NPPs

International Nuclear Information System (INIS)

Troyanov, M.F.; Poplavskij, V.M.; Sidorov, G.I.; Bondarenko, A.V.; Chebeskov, A.N.; Chushkin, V.N.; Karabash, A.A.; Krichko, A.A.; Maloletnev, A.S.

1998-01-01

With the present-day challenge of efficient use of low-grade coals and current restructuring of coal industry in the Russian Federation, it is urgent to organise the motor fuel production by the synthesis from low grade coals and heavy petroleum residues. With this objective in view, the Institute of Physics and Power Engineering of RF Minatom and Combustible Resources Institute of RF Mintopenergo proposed a project of a standard nuclear power technology complex for synthetic liquid fuel (SLF) production using fast neutron reactors for power supply. The proposed project has two main objectives: (1) Engineering and economical optimization of the nuclear power supply for SLF production; and (2) Engineering and economical optimization of the SLF production by hydrogenisation of brown coals and heavy petroleum residues with a complex development of advanced coal chemistry. As a first approach, a scheme is proposed with the use of existing reactor cooling equipment, in particular, steam generators of BN-600, limiting the effect on safety of reactor facility operation at minimum in case of deviations and abnormalities in the operation of technological complex. The possibility to exclude additional requirements to the equipment for nuclear facility cooling was also taken into account. It was proposed to use an intermediate steam-water circuit between the secondary circuit sodium and the coolant to heat the technological equipment. The only change required for the BN-600 equipment will be the replacement of sections of intermediate steam superheaters at the section of main steam superheaters. The economic aspects of synthetic motor fuel production proposed by the joint project depend on the evaluation of integral balances: thermal power engineering, chemical technology, the development of advanced large scale coal chemistry of high profitability; utilisation of ash and precious microelements in waste-free technology; production of valuable isotopes; radical solution of
CFD modeling of a boiler's tubes rupture

Energy Technology Data Exchange (ETDEWEB)

Rahimi, Masoud; Khoshhal, Abbas; Shariati, Seyed Mehdi [Chemical Engineering Department, Faculty of Engineering, Razi University, Kermanshah (Iran)

2006-12-15

This paper reports the results of a study on the reason for tubes damage in the superheater Platen section of the 320MW Bisotoun power plant, Iran. The boiler has three types of superheater tubes and the damage occurs in a series of elbows belongs to the long tubes. A three-dimensional modeling was performed using an in-house computational fluid dynamics (CFD) code in order to explore the reason. The code has ability of simultaneous solving of the continuity, the Reynolds-Averaged Navier-Stokes (RANS) equations and employing the turbulence, combustion and radiation models. The whole boiler including; walls, burners, air channels, three types of tubes, etc., was modeled in the real scale. The boiler was meshed into almost 2,000,000 tetrahedral control volumes and the standard k-{epsilon} turbulence model and the Rosseland radiation model were used in the model. The theoretical results showed that the inlet 18.9MPa saturated steam becomes superheated inside the tubes and exit at a pressure of 17.8MPa. The predicted results showed that the temperature of the steam and tube's wall in the long tubes is higher than the short and medium size tubes. In addition, the predicted steam mass flow rate in the long tube was lower than other ones. Therefore, it was concluded that the main reason for the rupture in the long tubes elbow is changing of the tube's metal microstructure due to working in a temperature higher than the design temperature. In addition, the structural fatigue tension makes the last elbow of the long tube more ready for rupture in comparison with the other places. The concluded result was validated by observations from the photomicrograph of the tube's metal samples taken from the damaged and undamaged sections. (author)
CFD modeling of a boiler's tubes rupture

International Nuclear Information System (INIS)

Rahimi, Masoud; Khoshhal, Abbas; Shariati, Seyed Mehdi

2006-01-01

This paper reports the results of a study on the reason for tubes damage in the superheater Platen section of the 320 MW Bisotoun power plant, Iran. The boiler has three types of superheater tubes and the damage occurs in a series of elbows belongs to the long tubes. A three-dimensional modeling was performed using an in-house computational fluid dynamics (CFD) code in order to explore the reason. The code has ability of simultaneous solving of the continuity, the Reynolds-Averaged Navier-Stokes (RANS) equations and employing the turbulence, combustion and radiation models. The whole boiler including; walls, burners, air channels, three types of tubes, etc., was modeled in the real scale. The boiler was meshed into almost 2,000,000 tetrahedral control volumes and the standard k-ε turbulence model and the Rosseland radiation model were used in the model. The theoretical results showed that the inlet 18.9 MPa saturated steam becomes superheated inside the tubes and exit at a pressure of 17.8 MPa. The predicted results showed that the temperature of the steam and tube's wall in the long tubes is higher than the short and medium size tubes. In addition, the predicted steam mass flow rate in the long tube was lower than other ones. Therefore, it was concluded that the main reason for the rupture in the long tubes elbow is changing of the tube's metal microstructure due to working in a temperature higher than the design temperature. In addition, the structural fatigue tension makes the last elbow of the long tube more ready for rupture in comparison with the other places. The concluded result was validated by observations from the photomicrograph of the tube's metal samples taken from the damaged and undamaged sections
Sulfation of corrosive alkali chlorides by ammonium sulfate in a biomass fired CFB boiler

Energy Technology Data Exchange (ETDEWEB)

Brostroem, Markus; Backman, Rainer; Nordin, Anders [Energy Technology and Thermal Process Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden); Kassman, Haakan [Vattenfall Power Consultant AB, Box 1046, SE-611 29 Nykoeping (Sweden); Helgesson, Anna; Berg, Magnus; Andersson, Christer [Vattenfall Research and Development AB, SE-814 26 Aelvkarleby (Sweden)

2007-12-15

Biomass and waste derived fuels contain relatively high amounts of alkali and chlorine, but contain very little sulfur. Combustion of such fuels can result in increased deposit formation and superheater corrosion. These problems can be reduced by using a sulfur containing additive, such as ammonium sulfate, which reacts with the alkali chlorides and forms less corrosive sulfates. Ammonium sulfate injection together with a so-called in situ alkali chloride monitor (IACM) is patented and known as ''ChlorOut''. IACM measures the concentrations of alkali chlorides (mainly KCl in biomass combustion) at superheater temperatures. Tests with and without spraying ammonium sulfate into the flue gases have been performed in a 96MW{sub th}/25MW{sub e} circulating fluidized bed (CFB) boiler. The boiler was fired mainly with bark and a chlorine containing waste. KCl concentration was reduced from more than 15 ppm to approximately 2 ppm during injection of ammonium sulfate. Corrosion probe measurements indicated that both deposit formation and material loss due to corrosion were decreased using the additive. Analysis of the deposits showed significantly higher concentration of sulfur and almost no chlorine in the case with ammonium sulfate. Results from impactor measurements supported that KCl was sulfated to potassium sulfate by the additive. (author)
Drift scale test status report (Chapters 1-9)

Energy Technology Data Exchange (ETDEWEB)

Lin, W., LLNL

1998-07-01

The Drift-Scale Test (DST) is one of the thermal tests being conducted in the Exploratory Studies Facility (ESF) at Yucca Mountain, Nevada, site of the potential repository for high-level nuclear waste. One of the DST`s major objectives is to study the coupled thermal-hydrologic-chemical-mechanical (THCM) processes at the potential repository`s horizon. The objectives, test design, and test layouts of the DST are included in a previous test design report. this report present results and analysis of several difference measurements made in the DST by researchers at Lawrence Livermore National Laboratory through the second quarter of the heating phase. Sections 1.1 and 1.2 describe the layout of the DST and the boreholes and instrumentation used to monitor the THCM processes in the rock of associated drifts. Section 2 presents an analysis of temperature data for the test through the end of May 1998. Sections 3 and 4 present results of electrical resistance tomography and neutron logging measurements, respectively. These two sets of measurements are designed to determine the movement of moisture in the test. Results of a series of geochemical measurements made on gas and water samples are presented in Section 5. The purpose of these measurements is to monitor the chemical processes occurring in the DST. Section 6 presents results of thermohydrologic modeling analysis of the test, and Section 7 presents data collected via the laboratory testing for characterization of the hydrologic properties of the rock forming the DST. A brief analysis of barometric pressure and humidity data collected through the end of May 1998 is discussed in Section 8, along with temperature data for the bulkhead. Finally, Section 9 presented an evaluation of sensors used in the DST.
Augmented Cross-Sectional Studies with Abbreviated Follow-up for Estimating HIV Incidence

OpenAIRE

Claggett, B.; Lagakos, S.W.; Wang, R.

2011-01-01

Cross-sectional HIV incidence estimation based on a sensitive and less-sensitive test offers great advantages over the traditional cohort study. However, its use has been limited due to concerns about the false negative rate of the less-sensitive test, reflecting the phenomenon that some subjects may remain negative permanently on the less-sensitive test. Wang and Lagakos (2010) propose an augmented cross-sectional design which provides one way to estimate the size of the infected population ...
Optimization of specimen preparation of thin cell section for AFM observation

Energy Technology Data Exchange (ETDEWEB)

Li Xinhui [Nanobiology Laboratory, Bio-X Life Science Research Center, School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240 (China); Ji Tong [Department of Oral and Maxillofacial Surgery, School of Stomatology, Affiliated Ninth People' s Hospital, Medical School, Shanghai Jiao Tong University, Shanghai 200011 (China); Hu Jun [Nanobiology Laboratory, Bio-X Life Science Research Center, School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240 (China); Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Sun Jielin [Nanobiology Laboratory, Bio-X Life Science Research Center, School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240 (China)], E-mail: jlsun@sjtu.edu.cn

2008-08-15

High resolution imaging of intracellular structures of ultrathin cell section samples is critical to the performance of precise manipulation by atomic force microscopy (AFM). Here, we test the effect of multiple factors during section sample preparation on the quality of the AFM image. These factors include the embedding materials, the annealing process of the specimen block, section thickness, and section side. We found that neither the embedding materials nor the temperature and speed of the annealing process has any effect on AFM image resolution. However, the section thickness and section side significantly affect the surface topography and AFM image resolution. By systematically testing the image quality of both sides of cell sections over a wide range of thickness (40-1000 nm), we found that the best resolution was obtained with upper-side sections approximately 50-100 nm thick. With these samples, we could observe precise structure details of the cell, including its membrane, nucleoli, and other organelles. Similar results were obtained for other cell types, including Tca8113, C6, and ECV-304. In brief, by optimizing the condition of ultrathin cell section preparation, we were able to obtain high resolution intracellular AFM images, which provide an essential basis for further AFM manipulation.
The safe motherhood referral system to reduce cesarean sections and perinatal mortality - a cross-sectional study [1995-2006

Directory of Open Access Journals (Sweden)

Rudge Marilza VC

2011-11-01

Full Text Available Abstract Background In 2000, the eight Millennium Development Goals (MDGs set targets for reducing child mortality and improving maternal health by 2015. Objective To evaluate the results of a new education and referral system for antenatal/intrapartum care as a strategy to reduce the rates of Cesarean sections (C-sections and maternal/perinatal mortality. Methods Design: Cross-sectional study. Setting: Department of Gynecology and Obstetrics, Botucatu Medical School, Sao Paulo State University/UNESP, Brazil. Population: 27,387 delivering women and 27,827 offspring. Data collection: maternal and perinatal data between 1995 and 2006 at the major level III and level II hospitals in Botucatu, Brazil following initiation of a safe motherhood education and referral system. Main outcome measures: Yearly rates of C-sections, maternal (/100,000 LB and perinatal (/1000 births mortality rates at both hospitals. Data analysis: Simple linear regression models were adjusted to estimate the referral system's annual effects on the total number of deliveries, C-section and perinatal mortality ratios in the two hospitals. The linear regression were assessed by residual analysis (Shapiro-Wilk test and the influence of possible conflicting observations was evaluated by a diagnostic test (Leverage, with p Results Over the time period evaluated, the overall C-section rate was 37.3%, there were 30 maternal deaths (maternal mortality ratio = 109.5/100,000 LB and 660 perinatal deaths (perinatal mortality rate = 23.7/1000 births. The C-section rate decreased from 46.5% to 23.4% at the level II hospital while remaining unchanged at the level III hospital. The perinatal mortality rate decreased from 9.71 to 1.66/1000 births and from 60.8 to 39.6/1000 births at the level II and level III hospital, respectively. Maternal mortality ratios were 16.3/100,000 LB and 185.1/100,000 LB at the level II and level III hospitals. There was a shift from direct to indirect causes of
Effect of evaporation section and condensation section length on thermal performance of flat plate heat pipe

International Nuclear Information System (INIS)

Wang Shuangfeng; Chen Jinjian; Hu Yanxin; Zhang Wei

2011-01-01

Flat plate heat pipes (FPHPs) are one of the available technologies to deal with the high density electronic cooling problem due to their high thermal conductivity, reliability, and low weight penalty. A series of experiments were performed to investigate the effect of evaporation and condensation length on thermal performance of flat plate heat pipes. In the experiments, the FPHP had heat transfer length of 255 mm and width of 25 mm, and pure water was used as the working fluid. The results show that comparing to vapor chamber, the FPHP could realize long-distance heat transfer; comparing to the traditional heat pipe, the FPHP has large area contact with heat sources; the thermal resistance decreased and the heat transfer limit increased with the increase of evaporation section length; the FPHP would dry out at a lower heating power with the increase of condensation section length, which indicated that the heat transfer limit decreased, but the evaporator temperature also decreased; when the condensation section length approached to evaporation section length, the FPHP had a better thermal performance. - Highlights: → A strip sintered FPHP is proposed and tested. → The total heat transfer length reaches 255 mm → The efficiency of heat transport reaches 94.4%. → When the condensation section length approached to evaporation section length, the FPHP has better overall performance.
Corrosivities in a pilot-scale combustor of a British and two Illinois coals with varying chlorine contents

Science.gov (United States)

Chou, I.-Ming; Lytle, J.M.; Kung, S.C.; Ho, K.K.

2000-01-01

Many US boiler manufacturers have recommended limits on the chlorine (Cl) content (< 0.25% or < 0.3%) of coals to be used in their boilers. These limits were based primarily on extrapolation of British coal data to predict the probable corrosion behavior of US coals. Even though Cl-related boiler corrosion has not been reported by US utilities burning high-Cl Illinois coals, the manufacturer's limits affect the marketability of high-Cl Illinois coals. This study measured the relative rates of corrosion caused by two high-Cl coals (British and Illinois) and one low-Cl Illinois baseline coal under identical pilot-scale combustion conditions for about 1000 h which gave reliable comparisons. Temperatures used reflected conditions in boiler superheaters. The corrosion probes were fabricated from commercial alloy 304SS frequently used at the hottest superheater section of utility boilers. The results showed no evidence of direct correlation between the coal chlorine content and rate of corrosion. A correlation between the rate of corrosion and the metal temperature was obvious. The results suggested that the different field histories of corrosivity from burning high-Cl Illinois coal and high-Cl British coal occurred because of different metal temperatures operated in US and UK utility boilers. The results of this study can be combined into a database, which could be used for lifting the limits on chlorine contents of coals burned in utility boilers in the US.
On JALT 95: Curriculum and Evaluation. Proceedings of the JALT International Conference on Language Teaching/Learning (22nd, Nagoya, Japan, November 1995). Section Seven: Testing and Evaluation.

Science.gov (United States)

Brown, James Dean; And Others

This section contains conference papers on testing and evaluation in second language teaching. They include: "English Language Entrance Examinations in Japan: Problems and Solutions" (James Dean Brown); "Reliability and a Learner Style Questionnaire" (Dale T. Griffee); "Does It Work?" Evaluating Language Learning Tasks" (Rod Ellis); "Communicative…
The Alcohol Use Disorders Identification Test for Consumption (AUDIT-C is more useful than pre-existing laboratory tests for predicting hazardous drinking: a cross-sectional study

Directory of Open Access Journals (Sweden)

Hideki Fujii

2016-05-01

Full Text Available Abstract Background It is important to screen for alcohol consumption and drinking customs in a standardized manner. The aim of this study was 1 to investigate whether the AUDIT score is useful for predicting hazardous drinking using optimal cutoff scores and 2 to use multivariate analysis to evaluate whether the AUDIT score was more useful than pre-existing laboratory tests for predicting hazardous drinking. Methods A cross-sectional study using the Alcohol Use Disorders Identification Test (AUDIT was conducted in 334 outpatients who consulted our internal medicine department. The patients completed self-reported questionnaires and underwent a diagnostic interview, physical examination, and laboratory testing. Results Forty (23 % male patients reported daily alcohol consumption ≥ 40 g, and 16 (10 % female patients reported consumption ≥ 20 g. The optimal cutoff values of hazardous drinking were calculated using a 10-fold cross validation, resulting in an optimal AUDIT score cutoff of 8.2, with a sensitivity of 95.5 %, specificity of 87.0 %, false positive rate of 13.0 %, false negative rate of 4.5 %, and area under the receiver operating characteristic curve of 0.97. Multivariate analysis revealed that the most popular short version of the AUDIT consisting solely of its three consumption items (AUDIT-C and patient sex were significantly associated with hazardous drinking. The aspartate transaminase (AST/alanine transaminase (ALT ratio and mean corpuscular volume (MCV were weakly significant. Conclusions This study showed that the AUDIT score and particularly the AUDIT-C score were more useful than the AST/ALT ratio and MCV for predicting hazardous drinking.
Timed function tests, motor function measure, and quantitative thigh muscle MRI in ambulant children with Duchenne muscular dystrophy: A cross-sectional analysis.

Science.gov (United States)

Schmidt, Simone; Hafner, Patricia; Klein, Andrea; Rubino-Nacht, Daniela; Gocheva, Vanya; Schroeder, Jonas; Naduvilekoot Devasia, Arjith; Zuesli, Stephanie; Bernert, Guenther; Laugel, Vincent; Bloetzer, Clemens; Steinlin, Maja; Capone, Andrea; Gloor, Monika; Tobler, Patrick; Haas, Tanja; Bieri, Oliver; Zumbrunn, Thomas; Fischer, Dirk; Bonati, Ulrike

2018-01-01

The development of new therapeutic agents for the treatment of Duchenne muscular dystrophy has put a focus on defining outcome measures most sensitive to capture treatment effects. This cross-sectional analysis investigates the relation between validated clinical assessments such as the 6-minute walk test, motor function measure and quantitative muscle MRI of thigh muscles in ambulant Duchenne muscular dystrophy patients, aged 6.5 to 10.8 years (mean 8.2, SD 1.1). Quantitative muscle MRI included the mean fat fraction using a 2-point Dixon technique, and transverse relaxation time (T2) measurements. All clinical assessments were highly significantly inter-correlated with p muscle MRI values significantly correlated with all clinical assessments with the extensors showing the strongest correlation. In contrast to the clinical assessments, quantitative muscle MRI values were highly significantly correlated with age. In conclusion, the motor function measure and timed function tests measure disease severity in a highly comparable fashion and all tests correlated with quantitative muscle MRI values quantifying fatty muscle degeneration. Copyright © 2017 Elsevier B.V. All rights reserved.
Testing of a JEF-1 based WIMS-D cross section library for migration area and k-infinity predictions for LWHCR lattices

International Nuclear Information System (INIS)

Pelloni, S.; Stepanek, J.

1987-01-01

The cell code WIMSD4 is used for the analysis of PROTEUS-LWHCR experiments. A library for this code which is based on the European evaluation JEF-1 was produced at EIR using the Los Alamos NJOY system with its module WIMSR and the Canadian management code WILMA. In general, this library delivered more accurate eigenvalues and reaction rates than the WIMS-Standard and WIMS81 libraries did in comparison to experimental values from PROTEUS-LWHCR Cores 1-3. However, large discrepancies (up to about 10%) occured between calculated migration areas (M 2 ). Additional investigations have been undertaken to clarify this problem, since theoretical M 2 -values are needed for deducing k-infinity in the experiments. This has been done in the context of calculations for a reference LWHCR test lattice. The following major reasons for these deviations were found. First, the self-scattering term in non-moderators (P 0 matrix) in the JEF-1 library was not transport corrected. Second, Standard and JEF-1 libraries use infinite dilute cross sections for 238 U, whereas the WIMS81 library uses fully shielded cross sections. Third, the standard library uses the 'row' formula for the transport correction, whereas the 'inflow' formula is applied in the case of JEF-1 and WIMS81 libraries. Lastly, oxygen and 238 U scattering cross sections in the fast energy range are smaller in the case of the WIMS81 library. Differences in calculated k-infinity values between the currently used library and WIMS81 (up to 3%) come (in order of importance for the reference LWHCR lattice) mainly from resonance cross sections for 240 Pu capture, 238 U capture and 239 Pu fission. Recommendations have been made for generating a new JEF-1 library using updated versions of WIMSR and WILMA. (author)
Audit of HIV counselling and testing services among primary healthcare facilities in Cameroon: a protocol for a multicentre national cross-sectional study.

Science.gov (United States)

Tianyi, Frank-Leonel; Tochie, Joel Noutakdie; Agbor, Valirie Ndip; Kadia, Benjamin Momo

2018-03-01

HIV testing is an invaluable entry point to prevention, care and treatment services for people living with HIV and AIDS. Poor adherence to recommended protocols and guidelines reduces the performance of rapid diagnostic tests, leading to misdiagnosis and poor estimation of HIV seroprevalence. This study seeks to evaluate the adherence of primary healthcare facilities in Cameroon to recommended HIV counselling and testing (HCT) procedures and the impact this may have on the reliability of HIV test results. This will be an analytical cross-sectional study involving primary healthcare facilities from all the 10 regions of Cameroon, selected by a multistaged random sampling of primary care facilities in each region. The study will last for 9 months. A structured questionnaire will be used to collect general information concerning the health facility, laboratory and other departments involved in the HCT process. The investigators will directly observe at least 10 HIV testing processes in each facility and fill out the checklist accordingly. Clearance has been obtained from the National Ethical Committee to carry out the study. Informed consent will be sought from the patients to observe the HIV testing process. The final study will be published in a peer-reviewed journal and the findings presented to health policy-makers and the general public. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
46 CFR 113.05-7 - Environmental tests.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Environmental tests. 113.05-7 Section 113.05-7 Shipping... SYSTEMS AND EQUIPMENT General Provisions § 113.05-7 Environmental tests. Communication, alarm system, control, and monitoring equipment must meet the environmental tests of— (a) Section 4-9-7, Table 9, of ABS...
46 CFR 162.050-37 - Vibration test.

Science.gov (United States)

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Vibration test. 162.050-37 Section 162.050-37 Shipping...: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Pollution Prevention Equipment § 162.050-37 Vibration test. (a... paragraph (b) of this section. The test must be performed at an independent laboratory that has the...
9 CFR 113.33 - Mouse safety tests.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Mouse safety tests. 113.33 Section 113.33 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Procedures § 113.33 Mouse safety tests. One of the mouse safety tests provided in this section shall be...

HIV incidence in rural South Africa: comparison of estimates from longitudinal surveillance and cross-sectional cBED assay testing.

Directory of Open Access Journals (Sweden)

Till Bärnighausen

Full Text Available The BED IgG-Capture Enzyme Immunoassay (cBED assay, a test of recent HIV infection, has been used to estimate HIV incidence in cross-sectional HIV surveys. However, there has been concern that the assay overestimates HIV incidence to an unknown extent because it falsely classifies some individuals with non-recent HIV infections as recently infected. We used data from a longitudinal HIV surveillance in rural South Africa to measure the fraction of people with non-recent HIV infection who are falsely classified as recently HIV-infected by the cBED assay (the long-term false-positive ratio (FPR and compared cBED assay-based HIV incidence estimates to longitudinally measured HIV incidence.We measured the long-term FPR in individuals with two positive HIV tests (in the HIV surveillance, 2003-2006 more than 306 days apart (sample size n = 1,065. We implemented four different formulae to calculate HIV incidence using cBED assay testing (n = 11,755 and obtained confidence intervals (CIs by directly calculating the central 95(th percentile of incidence values. We observed 4,869 individuals over 7,685 person-years for longitudinal HIV incidence estimation. The long-term FPR was 0.0169 (95% CI 0.0100-0.0266. Using this FPR, the cross-sectional cBED-based HIV incidence estimates (per 100 people per year varied between 3.03 (95% CI 2.44-3.63 and 3.19 (95% CI 2.57-3.82, depending on the incidence formula. Using a long-term FPR of 0.0560 based on previous studies, HIV incidence estimates varied between 0.65 (95% CI 0.00-1.32 and 0.71 (95% CI 0.00-1.43. The longitudinally measured HIV incidence was 3.09 per 100 people per year (95% CI 2.69-3.52, after adjustment to the sex-age distribution of the sample used in cBED assay-based estimation.In a rural community in South Africa with high HIV prevalence, the long-term FPR of the cBED assay is substantially lower than previous estimates. The cBED assay performs well in HIV incidence estimation if the locally
Marine Hydrokinetic (MHK) Energy Conversion Research at UNH: From Fundamental Studies of Hydrofoil Sections, to Moderate Reynolds Number Turbine Tests in a Tow Tank, to Open Water Deployments at Tidal Energy Test Sites (Invited)

Science.gov (United States)

Wosnik, M.; Bachant, P.; Nedyalkov, I.; Rowell, M.; Dufresne, N.; Lyon, V.

2013-12-01

We report on research related to MHK turbines at the Center for Ocean Renewable Energy (CORE) at the University of New Hampshire (UNH). The research projects span varies scales, levels of complexity and environments - from fundamental studies of hydrofoil sections in a high speed water tunnel, to moderate Reynolds number turbine tests with inflow and wake studies in a large cross-section tow tank, to deployments of highly instrumented process models at tidal energy test sites in New England. A concerted effort over the past few years has brought significant new research infrastructure for marine hydrokinetic energy conversion online at UNH-CORE. It includes: a high-speed cavitation tunnel with independent control of velocity and pressure; a highly accurate tow mechanism, turbine test bed and wake traversing system for the 3.7m x 2.4m cross-section UNH tow tank; a 10.7m x 3.0m tidal energy test platform which can accommodate turbines up to 1.5m in diameter, for deployments at the UNH-CORE Tidal Energy Test Site in Great Bay Estuary, NH, a sheltered 'nursery site' suitable for intermediate scale tidal energy conversion device testing with peak currents typically above 2 m/s during each tidal cycle. Further, a large boundary layer wind tunnel, the new UNH Flow Physics Facility (W6.0m x H2.7m xL72m) is being used for detailed turbine wake studies, producing data and insight also applicable to MHK turbines in low Froude number deployments. Bi-directional hydrofoils, which perform equally well in either flow direction and could avoid the use of complex and maintenance-intensive yaw or blade pitch mechanisms, are being investigated theoretically, numerically and experimentally. For selected candidate shapes lift, drag, wake, and cavitation inception/desinence are measured. When combined with a cavitation inception model for MHK turbines, this information can be used to prescribe turbine design/operational parameters. Experiments were performed with a 1m diameter and 1m
Boiling nucleation

International Nuclear Information System (INIS)

Cole, R.

1974-01-01

Experimental results of flash evaporation of a pool of water subjected to sudden pressure drop are reported. The experiments were conducted with pure water at equilibrium temperatures between 40 to 80 0 C and with superheat in the range of about 3 to 5 0 C. Two distinct exponential decaying processes were identified for flash evaporation and the flashing time was found to decrease with an increase of equilibrium temperature and with the decrease of superheat. Basic experiments on flash evaporation of distilled water were conducted. However, the results may not be quantitatively applicable to seawater flash evaporators as the presence of salts in the seawater will considerably change the surface tension and in turn affect the nonequilibrium fraction
Characterization and Modeling of Recycled Pavement Sections

Science.gov (United States)

2017-12-01

Because of its documented cost and environmental benefits, cold central plant recycling (CCPR) has attracted the interest of local and state departments of transportation. In 2015 two test pavement sections with CCPR as base layers were constructed a...
A Closer Look at Chinese EFL Learners' Test-Wiseness Strategies in Reading Test

Science.gov (United States)

Haiyan, Miao; Rilong, Liu

2016-01-01

This paper reports on an investigation into the relationship of test-takers' use of test-wiseness strategies to Chinese EFL learners' reading test performance. A test-wiseness questionnaire was administered immediately after the final achievement test to probe into how learners thought while completing the reading section of the test. It was found…
Evolution, calibration, and operational characteristics of the two-dimensional test section of the Langley 0.3-meter transonic cryogenic tunnel

Science.gov (United States)

Ladson, Charles L.; Ray, Edward J.

1987-01-01

Presented is a review of the development of the world's first cryogenic pressure tunnel, the Langley 0.3-Meter Transonic Cryogenic Tunnel (0.3-m TCT). Descriptions of the instrumentation, data acquisition systems, and physical features of the two-dimensional 8- by 24-in, (20.32 by 60.96 cm) and advanced 13- by 13-in (33.02 by 33.02 cm) adaptive-wall test-section inserts of the 0.3-m TCT are included. Basic tunnel-empty Mach number distributions, stagnation temperature distributions, and power requirements are included. The Mach number capability of the facility is from about 0.20 to 0.90. Stagnation pressure can be varied from about 80 to 327 K.
ASME section XI: rules for inservice inspection of nuclear power plants -an introspection

Energy Technology Data Exchange (ETDEWEB)

John, P K; Anto, Y; Mungikar, C P; Wagh, P M [Nuclear Power Corporation of India Ltd., Tarapur (India). Tarapur Atomic Power Station

1994-12-31

Section XI of the ASME BPV code is addressed to the examination, test and inspection requirements of the components of nuclear power plants (NPPs). Since its inception in 1970, this code section has undergone vast changes -probably the most among other ASME BPV code sections. Section XI is full fledged and lays down requirements with regard to all preservice inspections, inservice inspection, repair and replacement of components, tests of system etc. Tarapur Atomic Power Station (TAPS) has the distinction of being one of the earliest BWR type NPPs in the world that has an inservice inspection programme organised in line with the ASME section XI requirements. This paper summarises the experiences gained from time to time using this code section and a few suggestions to prospective users. An effort is also made to explain the philosophy of inservice inspection from ASME section XI point of view. 3 refs.
ASME section XI: rules for inservice inspection of nuclear power plants -an introspection

International Nuclear Information System (INIS)

John, P.K.; Anto, Y.; Mungikar, C.P.; Wagh, P.M.

1994-01-01

Section XI of the ASME BPV code is addressed to the examination, test and inspection requirements of the components of nuclear power plants (NPPs). Since its inception in 1970, this code section has undergone vast changes -probably the most among other ASME BPV code sections. Section XI is full fledged and lays down requirements with regard to all preservice inspections, inservice inspection, repair and replacement of components, tests of system etc. Tarapur Atomic Power Station (TAPS) has the distinction of being one of the earliest BWR type NPPs in the world that has an inservice inspection programme organised in line with the ASME section XI requirements. This paper summarises the experiences gained from time to time using this code section and a few suggestions to prospective users. An effort is also made to explain the philosophy of inservice inspection from ASME section XI point of view. 3 refs
Determination of Optimum Cross-section for Oran Highway Revetment

Science.gov (United States)

Velioglu, Deniz; Sogut, Erdinc; Guler, Isikhan

2017-04-01

Revetments are shore parallel, sloping coastal structures which are built to provide protection from the negative effects of the sea. The revetment mentioned in this study is located in the City of Oran, Algeria and is currently under construction. This study investigates the determination of the optimum revetment cross section for Oran highway, considering both the hydraulic stability of the revetment and economy. The existence of cliffs in the region and the settlement of the City of Oran created a necessity to re-align Oran highway; therefore, it was shifted towards the Gulf of Oran. Approximately 1 km of the highway is to be constructed on the Mediterranean Sea due to the new alignment. In order to protect the sea side of the road from the adverse effects of the sea, a revetment was designed. The proposed cross section had an armour layer composed of 23 tons of antifer units and regular placement of armour units was recommended. In order to check the hydraulic stability of the proposed section, physical model tests were performed in the laboratory of LEM (Laboratoire d'Etudes Maritimes) in Algeria, using the pre-determined design wave conditions. The physical model tests revealed that the trunk of the revetment was totaly damaged. Accordingly, the proposed section was found insufficient and certain modifications were required. The first modification was made in the arrangement of armour units, changing them from regular to irregular. After testing the new cross section, it was observed that the revetment was vulnerable to breaking wave attack due to the toe geometry and thus the toe of the revetment had to be re-shaped. Therefore, the second option was to reduce the toe elevation. It was observed that even though the revetment trunk was safe, the damage in the toe was not in acceptable limits. The new cross section was found insufficient and as the final option, the weight of the antifer units used in the armour layer was increased, the toe length of the
Advantages obtained in radiation protection when using computerized radiography tests - CR (digital) in processing plants; Vantagens obtidas em radioprotecao quando do uso do ensaio de radiografia computadorizada - RC (digital) em plantas de processo

Energy Technology Data Exchange (ETDEWEB)

Jose, Joao Carlos Videira; Milani, Hilton Sergio B.; Paes, Eliseu Almir de Oliveira; Boita, Mario de [ARCtest Servicos Tecnicos de Inspecao e Manutencao Industrial Ltda., Sao Paulo, SP (Brazil)]. E-mail: tecnica@arctest.com.br; Souza, Laercio de; Serra, Flavio Augusto dos Santos [PETROBRAS, Paulinia, SP, RJ (Brazil). Refinaria do Planalto Paulista (REPLAN)]. E-mails: laerciosouza@petrobras.com.br; serra@petrobras.com.br

2002-07-01

During the year 2000, the ARCtest initiated the development of the research for adapting the Computerized Radiography - CR, originally conceived for medical applications, for the Industry, trying initially to attend the requirements of the processing plants, concerning to the detection of deterioration mechanisms (evaluation of the piping integrity). Due to the obtained excellent results, the possibility of utilization the Computerized Radiography - CR in the radiographic inspection were studied during the shutdown of the Catalytic Cracking Unit of the PETROBRAS-REPLAN, specifically in the replacement of the CO boiler superheater, where a large number of the small diameter welded joints have been predicted.
Natural convection heat transfer in a rectangular pool with volumetric heat sources

International Nuclear Information System (INIS)

Lee, Seung Dong; Lee, Kang Hee; Suh, Kune Y.

2003-01-01

Natural convection plays an important role in determining the thermal load from debris accumulated in the reactor vessel lower head during a severe accident. The heat transfer within the molten core material can be characterized by buoyancy-induced flows resulting from internal heating due to decay of fission products. The thermo-fluid dynamic characteristics of the molten pool depend strongly on the thermal boundary conditions. The spatial and temporal variation of heat flux on the pool wall boundaries and the pool superheat are mainly characterized by the natural convection flow inside the molten pool. In general, natural convection involving internal heat generation is delineated in terms of the modified Rayleigh number, Ra', which quantifies the internal heat source and hence the strength of buoyancy. The test section is of rectangular cavity whose length, width, and height are 500 mm, 80 mm, and 250 mm, respectively. A total of twenty-four T-type thermocouples were installed in the test loop to measure temperature distribution. Four T-type thermocouples were utilized to measure temperatures on the boundary. A direct heating method was adopted in this test to simulate the uniform heat generation. The experiments covered a range of Rayleigh number, Ra, between 4.87x10 7 and 2.32x10 14 and Prandtl number, Pr, between 0.7 and 3.98. Tests were conducted with water and air as simulant. The upper and lower boundary conditions were maintained at a uniform temperature of 10degC. (author)
Jet cross sections in electron-positron annihilation

International Nuclear Information System (INIS)

Sharpe, S.R.

1983-08-01

There are few, if any, detailed tests of QCD at present. I disucss the problems associated with testing QCD and argue that the three jet angular distribution in electron-positron annihilation is a good quantity to use because it minimizes the sensitivity to nonperturbative effects and provides a test of the detailed structure of QCD. However, for such a test to be possible, the perturbation expansion must be well behaved. I present a calculation of the perturbative corrections using two different generalizations of the Sterman-Weinberg two-jet cross section. I argue that because of the uncertainties in our understanding of hadronization it is necessary that the corrections to both these cross sections be small. In presenting the results I use the recent proof of Mukti and Sterman that all the logarithms can be resummed. I find that at Z-factory energies there is a substantial region of parameters defining the jets for which the correction is small, but that there is no such region at PEP/PETRA energies. This problem at PEP/PETRA energies is made worse by the results of a study of the effects of hadronization. Using a simple model I find very significant effects at PEP/PETRA energies that would make a test difficult. These effects do not, however, present problems at Z-factory energies. I conclude that, even if there are further theoretical advances, testing QCD at PEP/PETRA energies using the three-jet angular distribution will be very difficult. However, this distribution can be used to test QCD in a detailed way at Z-factory energies. The corrected results, furthermore, show a systematic difference from the lowest order result that may be measurable at Z-factory energies. If this effect could be measured it would provide a yet more detailed test of QCD, testing, for example, the three gluon coupling. 66 references
Fuzzy multivariable control of domestic heat pumps

International Nuclear Information System (INIS)

Underwood, C.P.

2015-01-01

Poor control has been identified as one of the reasons why recent field trials of domestic heat pumps in the UK have produced disappointing results. Most of the technology in use today uses a thermostatically-controlled fixed speed compressor with a mechanical expansion device. This article investigates improved control of these heat pumps through the design and evaluation of a new multivariable fuzzy logic control system utilising a variable speed compressor drive with capacity control linked through to evaporator superheat control. A new dynamic thermal model of a domestic heat pump validated using experimental data forms the basis of the work. The proposed control system is evaluated using median and extreme daily heating demand profiles for a typical UK house compared with a basic thermostatically-controlled alternative. Results show good tracking of the heating temperature and superheat control variables, reduced cycling and an improvement in performance averaging 20%. - Highlights: • A new dynamic model of a domestic heat pump is developed and validated. • A new multivariable fuzzy logic heat pump control system is developed/reported. • The fuzzy controller regulates both plant capacity and evaporator superheat degree. • Thermal buffer storage is also considered as well as compressor cycling. • The new controller shows good variable tracking and a reduction in energy of 20%.
Unit root tests for cross-sectionally dependent panels : The influence of observed factors

NARCIS (Netherlands)

Becheri, I.G.; Drost, F.C.; van den Akker, R.

This paper considers a heterogeneous panel unit root model with cross-sectional dependence generated by a factor structure—the factor common to all units being an observed covariate. The model is shown to be Locally Asymptotically Mixed Normal (LAMN), with the random part of the limiting Fisher
SHAMSI, 48 group cross-section library for fusion nucleonics analysis

International Nuclear Information System (INIS)

Ponti, C.; Abbas, Tayyab.

1982-01-01

A P 3 48 group coupled neutron gamma-ray (34 N - 14 G) cross-section library is produced and validated for neutronic studies in fusion reactor blanket/shield. This report describes the library content, the procedure adopted and the results of the calculations performed for testing the cross sections
Testing an ionization chamber with gaseous samples and measurements of the (n, alpha) reaction cross sections

CERN Document Server

Gledenov, Yu M; Salatskii, V I; Sedyshev, P V; Andrzejewski, J; Szalanski, P

1999-01-01

A new ionization chamber with gaseous samples (GIC) has been designed and tested on the thermal and resonance neutron beams of FLNP's neutron sources. The exposed gas volume serves as a target for neutrons. The obtained thermal cross sections for the sup 1 sup 7 O(n, alpha) sup 1 sup 4 C, sup 2 sup 1 Ne(n, alpha) sup 1 sup 8 O and sup 3 sup 6 Ar(n, alpha) sup 3 sup 3 S reactions are (233+-12) mb, (0.18+-0.09) mb and (5.43+-0.27) mb, respectively. These measurements have been performed on a pure beam of thermal neutrons from the high flux reactor IBR-2; and they demonstrated high efficiency and reliability of the method. Compared to samples on substrates, the application of gaseous samples makes the beam background essentially lower, and what is more important, the background component is totally absent due to the absence of Li and B microimpurities in gaseous samples while they do present in the samples on substrates. The method is also applicable to measurements with resonance neutrons. The recovery capabili...
Sexual behaviours, HIV testing, and the proportion of men at risk of transmitting and acquiring HIV in London, UK, 2000-13: a serial cross-sectional study.

Science.gov (United States)

Aghaizu, Adamma; Wayal, Sonali; Nardone, Anthony; Parsons, Victoria; Copas, Andrew; Mercey, Danielle; Hart, Graham; Gilson, Richard; Johnson, Anne M

2016-09-01

HIV incidence in men who have sex with men (MSM) in the UK has remained unchanged over the past decade despite increases in HIV testing and antiretroviral therapy (ART) coverage. In this study, we examine trends in sexual behaviours and HIV testing in MSM and explore the risk of transmitting and acquiring HIV. In this serial cross-sectional study, we obtained data from ten cross-sectional surveys done between 2000 and 2013, consisting of anonymous self-administered questionnaires and oral HIV antibody testing in MSM recruited in gay social venues in London, UK. Data were collected between October and January for all survey years up to 2008 and between February and August thereafter. All men older than 16 years were eligible to take part and fieldworkers attempted to approach all MSM in each venue and recorded refusal rates. Data were collected on demographic and sexual behavioural characteristics. We analysed trends over time using linear, logistic, and quantile regression. Of 13 861 questionnaires collected between 2000 and 2013, we excluded 1985 (124 had completed the survey previously or were heterosexual reporting no anal intercourse in the past year, and 1861 did not provide samples for antibody testing). Of the 11 876 eligible MSM recruited, 1512 (13%) were HIV positive, with no significant trend in HIV positivity over time. 35% (531 of 1505) of HIV-positive MSM had undiagnosed infection, which decreased non-linearly over time from 34% (45 of 131) to 24% (25 of 106; p=0·01), while recent HIV testing (ie, in the past year) increased from 26% (263 of 997) to 60% (467 of 777; pmove towards eradication of HIV. Public Health England. Copyright © 2016 Elsevier Ltd. All rights reserved.
Review of Section XI inservice inspection program effectiveness

International Nuclear Information System (INIS)

Cook, J.F. Sr.

1993-08-01

To evaluate the effectiveness of Section XI, Division 1, open-quotes Rules for Inservice Inspection of Nuclear Power Plant Components,close quotes of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, searches were performed of the Licensing Event Report and Nuclear Plant Reliability Data System computerized data bases, and a review was made of inservice inspection summary reports. It was found that the Section XI examinations and tests detect flaws in welds and plant components and result in subsequent corrective action. This study also shows that the format and topics of information provided in Section XI-prescribed inservice inspection summary reports vary widely
Review of Section XI inservice inspection program effectiveness

Energy Technology Data Exchange (ETDEWEB)

Cook, J.F. Sr.

1993-08-01

To evaluate the effectiveness of Section XI, Division 1, {open_quotes}Rules for Inservice Inspection of Nuclear Power Plant Components,{close_quotes} of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, searches were performed of the Licensing Event Report and Nuclear Plant Reliability Data System computerized data bases, and a review was made of inservice inspection summary reports. It was found that the Section XI examinations and tests detect flaws in welds and plant components and result in subsequent corrective action. This study also shows that the format and topics of information provided in Section XI-prescribed inservice inspection summary reports vary widely.
Organic research section. 1984 review and 1985 programs

International Nuclear Information System (INIS)

Glass, R.W.

1985-02-01

This report reviews the major activities and accomplishments of the Organic Research Section in 1984 and presents the 1985 work program. The three major areas of the Section's research work are non-metallic materials which includes applications and uses of plastics, petroleum products, coatings and elastomers; reactor waste management; and activity transport/decontamination of nuclear systems. In 1984, 50% of the Section's resources were used on studies in support of nuclear generation, 13% on reactor waste, and 37% on general activities and work in support of utilization, transmission and distribution, and thermal and hydraulic programs. About 60% of the section's work was supported by transfer and revenue funds as a result of urgent short-term work requirements which resulted in 68% of the work falling into the technical investigation, consulting and testing categories

Some links on this page may take you to non-federal websites. Their policies may differ from this site.